Julio Cesar Mateo (born August 2, 1977) is a Dominican professional baseball pitcher. The 6’0 tall 220 lb Mateo bats and throws right-handed. He was signed by the Seattle Mariners as a non-drafted free agent on May 15, 1996.
Professional career
Seattle Mariners
Mateo went 4–2 with a 1.74 ERA in 15 games, including two starts, for Dominican Summer League Mariners in 1996. He tossed two complete games and earned one save.
In 1997 Mateo went 3–1 with a 3.30 ERA in 13 outings, including six starts, for Arizona League Mariners.
With the Short-Season Everett AquaSox in 1998, Mateo went 3–3 with a 4.70 ERA and four saves in 28 relief appearances. He also allowed one run over 11⁄3 innings in his lone outing for the Class-A Advanced Lancaster JetHawks.
Mateo went 1–3 with a 4.34 ERA and four saves in 20 outings for the Class-A Wisconsin Timber Rattlers in 1999.
Again with Class-A Wisconsin in 2000, Mateo went 4–8 with a 4.19 ERA and four saves in 36 outings, including one start.
He went 5–4 with a 2.86 ERA and a career-high 26 saves in 56 outings for the Class-A Advanced San Bernardino Stampede in 2001.

Trophies 
Milestones
Former Youth Teams 
None found...
None found...
| SO/BB | MLB | 2007 | 0.80 |
| SO9 | MLB | 2007 | 3.0 |
| BB9 | MLB | 2007 | 3.8 |
| HR9 | MLB | 2007 | 0.0 |
| H9 | MLB | 2007 | 9.0 |
| WHIP | MLB | 2007 | 1.417 |
| Fielding Independent Pitching | MLB | 2007 | 3.82 |
| ERA+ | MLB | 2007 | 120 |
| Batters Faced | MLB | 2007 | 52 |
| Wild Pitches | MLB | 2007 | 0 |
| Balks | MLB | 2007 | 0 |
| Times Hit by a Pitch | MLB | 2007 | 0 |
| Strikeouts | MLB | 2007 | 4 |
| Intentional Bases on Balls | MLB | 2007 | 1 |
| Bases on Balls/Walks | MLB | 2007 | 5 |
| Home Runs Allowed | MLB | 2007 | 0 |
| Earned Runs Allowed | MLB | 2007 | 5 |
| Runs Allowed | MLB | 2007 | 5 |
| Hits Allowed | MLB | 2007 | 12 |
| Innings Pitched | MLB | 2007 | 12.0 |
| Saves | MLB | 2007 | 0 |
| Shutouts | MLB | 2007 | 0 |
| Complete Games | MLB | 2007 | 0 |
| Games Finished | MLB | 2007 | 1 |
| Games Started | MLB | 2007 | 0 |
| Games Pitched | MLB | 2007 | 9 |
| ERA | MLB | 2007 | 3.75 |
| Win-Loss Percentage | MLB | 2007 | 1.000 |
| Loss | MLB | 2007 | 0 |
| Wins | MLB | 2007 | 1 |
| Wins Above Replacement for Pitchers | MLB | 2007 | 0.2 |
|
|
| SO/BB | MLB | 2006 | 1.41 |
| SO9 | MLB | 2006 | 5.2 |
| BB9 | MLB | 2006 | 3.7 |
| HR9 | MLB | 2006 | 1.0 |
| H9 | MLB | 2006 | 10.4 |
| WHIP | MLB | 2006 | 1.565 |
| Fielding Independent Pitching | MLB | 2006 | 4.84 |
| ERA+ | MLB | 2006 | 106 |
| Batters Faced | MLB | 2006 | 241 |
| Wild Pitches | MLB | 2006 | 1 |
| Balks | MLB | 2006 | 0 |
| Home Runs Allowed | MLB | 2006 | 6 |
| Earned Runs Allowed | MLB | 2006 | 25 |
| Runs Allowed | MLB | 2006 | 27 |
| Hits Allowed | MLB | 2006 | 62 |
| Innings Pitched | MLB | 2006 | 53.2 |
| Saves | MLB | 2006 | 0 |
| Shutouts | MLB | 2006 | 0 |
| Complete Games | MLB | 2006 | 0 |
| Games Finished | MLB | 2006 | 13 |
| Games Started | MLB | 2006 | 0 |
| Games Pitched | MLB | 2006 | 48 |
| ERA | MLB | 2006 | 4.19 |
| Win-Loss Percentage | MLB | 2006 | .692 |
| Loss | MLB | 2006 | 4 |
| Wins | MLB | 2006 | 9 |
| Wins Above Replacement for Pitchers | MLB | 2006 | 0.2 |
| Positions Played | MLB | 2006 | 1 |
| Intentional Bases on Balls | MLB | 2006 | 0 |
| Sacrifice Flies | MLB | 2006 | 0 |
| Sacrifice Hits | MLB | 2006 | 0 |
| Times Hit by a Pitch | MLB | 2006 | 0 |
| GIDP | MLB | 2006 | 0 |
| Total Bases | MLB | 2006 | 0 |
| Strikeouts | MLB | 2006 | 0 |
| Bases on Balls/Walks | MLB | 2006 | 0 |
| Caught Stealing | MLB | 2006 | 0 |
| Stolen Bases | MLB | 2006 | 0 |
| Runs Batted In | MLB | 2006 | 0 |
| Home Runs | MLB | 2006 | 0 |
| Triples | MLB | 2006 | 0 |
| Doubles | MLB | 2006 | 0 |
| Hits | MLB | 2006 | 0 |
| Runs Scored | MLB | 2006 | 0 |
| At Bats | MLB | 2006 | 0 |
| Plate Appearances | MLB | 2006 | 0 |
| Games Played | MLB | 2006 | 5 |
| Wins Above Replacement for position players | MLB | 2006 | 0.0 |
|
|
| SO/BB | MLB | 2005 | 3.06 |
| SO9 | MLB | 2005 | 5.3 |
| BB9 | MLB | 2005 | 1.7 |
| HR9 | MLB | 2005 | 1.2 |
| H9 | MLB | 2005 | 8.0 |
| WHIP | MLB | 2005 | 1.087 |
| Fielding Independent Pitching | MLB | 2005 | 4.42 |
| ERA+ | MLB | 2005 | 138 |
| Batters Faced | MLB | 2005 | 364 |
| Wild Pitches | MLB | 2005 | 1 |
| Balks | MLB | 2005 | 0 |
| Home Runs Allowed | MLB | 2005 | 12 |
| Earned Runs Allowed | MLB | 2005 | 30 |
| Runs Allowed | MLB | 2005 | 32 |
| Hits Allowed | MLB | 2005 | 79 |
| Innings Pitched | MLB | 2005 | 88.1 |
| Saves | MLB | 2005 | 0 |
| Shutouts | MLB | 2005 | 0 |
| Complete Games | MLB | 2005 | 0 |
| Games Finished | MLB | 2005 | 7 |
| Games Started | MLB | 2005 | 1 |
| Games Pitched | MLB | 2005 | 55 |
| ERA | MLB | 2005 | 3.06 |
| Win-Loss Percentage | MLB | 2005 | .333 |
| Loss | MLB | 2005 | 6 |
| Wins | MLB | 2005 | 3 |
| Wins Above Replacement for Pitchers | MLB | 2005 | 1.9 |
| Positions Played | MLB | 2005 | 1 |
| Intentional Bases on Balls | MLB | 2005 | 0 |
| Sacrifice Flies | MLB | 2005 | 0 |
| Sacrifice Hits | MLB | 2005 | 0 |
| Times Hit by a Pitch | MLB | 2005 | 0 |
| GIDP | MLB | 2005 | 0 |
| Total Bases | MLB | 2005 | 0 |
| Strikeouts | MLB | 2005 | 0 |
| Bases on Balls/Walks | MLB | 2005 | 0 |
| Caught Stealing | MLB | 2005 | 0 |
| Stolen Bases | MLB | 2005 | 0 |
| Runs Batted In | MLB | 2005 | 0 |
| Home Runs | MLB | 2005 | 0 |
| Triples | MLB | 2005 | 0 |
| Doubles | MLB | 2005 | 0 |
| Hits | MLB | 2005 | 0 |
| Runs Scored | MLB | 2005 | 0 |
| At Bats | MLB | 2005 | 0 |
| Plate Appearances | MLB | 2005 | 0 |
| Games Played | MLB | 2005 | 4 |
| Wins Above Replacement for position players | MLB | 2005 | 0.0 |
|
|
| SO/BB | MLB | 2004 | 2.69 |
| SO9 | MLB | 2004 | 6.7 |
| BB9 | MLB | 2004 | 2.5 |
| HR9 | MLB | 2004 | 1.7 |
| H9 | MLB | 2004 | 8.7 |
| WHIP | MLB | 2004 | 1.249 |
| Fielding Independent Pitching | MLB | 2004 | 5.13 |
| ERA+ | MLB | 2004 | 97 |
| Batters Faced | MLB | 2004 | 248 |
| Wild Pitches | MLB | 2004 | 2 |
| Balks | MLB | 2004 | 0 |
| Home Runs Allowed | MLB | 2004 | 11 |
| Earned Runs Allowed | MLB | 2004 | 30 |
| Runs Allowed | MLB | 2004 | 30 |
| Hits Allowed | MLB | 2004 | 56 |
| Innings Pitched | MLB | 2004 | 57.2 |
| Saves | MLB | 2004 | 1 |
| Shutouts | MLB | 2004 | 0 |
| Complete Games | MLB | 2004 | 0 |
| Games Finished | MLB | 2004 | 9 |
| Games Started | MLB | 2004 | 0 |
| Games Pitched | MLB | 2004 | 45 |
| ERA | MLB | 2004 | 4.68 |
| Win-Loss Percentage | MLB | 2004 | .333 |
| Loss | MLB | 2004 | 2 |
| Wins | MLB | 2004 | 1 |
| Wins Above Replacement for Pitchers | MLB | 2004 | 0.3 |
| Positions Played | MLB | 2004 | 1 |
| Intentional Bases on Balls | MLB | 2004 | 0 |
| Sacrifice Flies | MLB | 2004 | 0 |
| Sacrifice Hits | MLB | 2004 | 0 |
| Times Hit by a Pitch | MLB | 2004 | 0 |
| GIDP | MLB | 2004 | 0 |
| Total Bases | MLB | 2004 | 0 |
| Strikeouts | MLB | 2004 | 0 |
| Bases on Balls/Walks | MLB | 2004 | 0 |
| Caught Stealing | MLB | 2004 | 0 |
| Stolen Bases | MLB | 2004 | 0 |
| Runs Batted In | MLB | 2004 | 0 |
| Home Runs | MLB | 2004 | 0 |
| Triples | MLB | 2004 | 0 |
| Doubles | MLB | 2004 | 0 |
| Hits | MLB | 2004 | 0 |
| Runs Scored | MLB | 2004 | 0 |
| At Bats | MLB | 2004 | 0 |
| Plate Appearances | MLB | 2004 | 0 |
| Games Played | MLB | 2004 | 4 |
| Wins Above Replacement for position players | MLB | 2004 | 0.0 |
|
|
| SO/BB | MLB | 2003 | 5.46 |
| SO9 | MLB | 2003 | 7.5 |
| BB9 | MLB | 2003 | 1.4 |
| HR9 | MLB | 2003 | 1.5 |
| H9 | MLB | 2003 | 7.2 |
| WHIP | MLB | 2003 | 0.957 |
| Fielding Independent Pitching | MLB | 2003 | 4.13 |
| ERA+ | MLB | 2003 | 137 |
| Batters Faced | MLB | 2003 | 338 |
| Wild Pitches | MLB | 2003 | 1 |
| Balks | MLB | 2003 | 1 |
| Home Runs Allowed | MLB | 2003 | 14 |
| Earned Runs Allowed | MLB | 2003 | 30 |
| Runs Allowed | MLB | 2003 | 32 |
| Hits Allowed | MLB | 2003 | 69 |
| Innings Pitched | MLB | 2003 | 85.2 |
| Saves | MLB | 2003 | 1 |
| Shutouts | MLB | 2003 | 0 |
| Complete Games | MLB | 2003 | 0 |
| Games Finished | MLB | 2003 | 17 |
| Games Started | MLB | 2003 | 0 |
| Games Pitched | MLB | 2003 | 50 |
| ERA | MLB | 2003 | 3.15 |
| Win-Loss Percentage | MLB | 2003 | 1.000 |
| Loss | MLB | 2003 | 0 |
| Wins | MLB | 2003 | 4 |
| Wins Above Replacement for Pitchers | MLB | 2003 | 1.4 |
| Positions Played | MLB | 2003 | 1 |
| Intentional Bases on Balls | MLB | 2003 | 0 |
| Sacrifice Flies | MLB | 2003 | 0 |
| Sacrifice Hits | MLB | 2003 | 0 |
| Times Hit by a Pitch | MLB | 2003 | 0 |
| GIDP | MLB | 2003 | 0 |
| Total Bases | MLB | 2003 | 0 |
| Strikeouts | MLB | 2003 | 0 |
| Bases on Balls/Walks | MLB | 2003 | 0 |
| Caught Stealing | MLB | 2003 | 0 |
| Stolen Bases | MLB | 2003 | 0 |
| Runs Batted In | MLB | 2003 | 0 |
| Home Runs | MLB | 2003 | 0 |
| Triples | MLB | 2003 | 0 |
| Doubles | MLB | 2003 | 0 |
| Hits | MLB | 2003 | 0 |
| Runs Scored | MLB | 2003 | 0 |
| At Bats | MLB | 2003 | 0 |
| Plate Appearances | MLB | 2003 | 0 |
| Games Played | MLB | 2003 | 1 |
| Wins Above Replacement for position players | MLB | 2003 | 0.0 |
|
|
| SO/BB | MLB | 2002 | 1.25 |
| SO9 | MLB | 2002 | 6.4 |
| BB9 | MLB | 2002 | 5.1 |
| HR9 | MLB | 2002 | 0.9 |
| H9 | MLB | 2002 | 8.6 |
| WHIP | MLB | 2002 | 1.524 |
| Fielding Independent Pitching | MLB | 2002 | 4.63 |
| ERA+ | MLB | 2002 | 101 |
| Batters Faced | MLB | 2002 | 94 |
| Wild Pitches | MLB | 2002 | 1 |
| Balks | MLB | 2002 | 0 |
| Home Runs Allowed | MLB | 2002 | 2 |
| Earned Runs Allowed | MLB | 2002 | 10 |
| Runs Allowed | MLB | 2002 | 10 |
| Hits Allowed | MLB | 2002 | 20 |
| Innings Pitched | MLB | 2002 | 21.0 |
| Saves | MLB | 2002 | 0 |
| Shutouts | MLB | 2002 | 0 |
| Complete Games | MLB | 2002 | 0 |
| Games Finished | MLB | 2002 | 7 |
| Games Started | MLB | 2002 | 0 |
| Games Pitched | MLB | 2002 | 12 |
| ERA | MLB | 2002 | 4.29 |
| Loss | MLB | 2002 | 0 |
| Wins | MLB | 2002 | 0 |
| Wins Above Replacement for Pitchers | MLB | 2002 | 0.2 |
| Positions Played | MLB | 2002 | 1 |
| Intentional Bases on Balls | MLB | 2002 | 0 |
| Sacrifice Flies | MLB | 2002 | 0 |
| Sacrifice Hits | MLB | 2002 | 0 |
| Times Hit by a Pitch | MLB | 2002 | 0 |
| GIDP | MLB | 2002 | 0 |
| Total Bases | MLB | 2002 | 0 |
| Strikeouts | MLB | 2002 | 0 |
| Bases on Balls/Walks | MLB | 2002 | 0 |
| Caught Stealing | MLB | 2002 | 0 |
| Stolen Bases | MLB | 2002 | 0 |
| Runs Batted In | MLB | 2002 | 0 |
| Home Runs | MLB | 2002 | 0 |
| Triples | MLB | 2002 | 0 |
| Doubles | MLB | 2002 | 0 |
| Hits | MLB | 2002 | 0 |
| Runs Scored | MLB | 2002 | 0 |
| At Bats | MLB | 2002 | 0 |
| Plate Appearances | MLB | 2002 | 0 |
| Games Played | MLB | 2002 | 1 |
| Wins Above Replacement for position players | MLB | 2002 | 0.0 |
|