Jeffrey Michael Bajenaru
- Bats Right, Throws Right
- Height 6' 1", Weight 190 lb.
- School University of California, Riverside, Riverside Community College, University of Oklahoma
- High School Ruben S. Ayala High School
- Debut September 4, 2004
- Final Game August 7, 2006
- Born March 21, 1978 in Pomona, CA USA
Jeff Bajenaru was drafted in the 13th round of the 1998 amateur draft by the Oakland Athletics out of community college. He chose instead to attend the University of Oklahoma, where he got his degree. In 1999, he went 3-0 with 8 saves and a 3.20 ERA for the Sooners and hit .312/.424/.502. Drafted by the Chicago White Sox in 1999, he did not sign for almost a year. Still with Oklahoma in 2000, he hit .342/.392/.551, making the Big 12 All-Conference team as an outfielder. On the hill, he went 1-2 with a 2.61 ERA and a conference-leading 20 saves.
Bajenaru was signed by scout John Kazanas as an undrafted free agent in June 2000. He made his pro debut that summer in rookie ball with the Bristol Sox and went 1-1 with 5 saves and a 3.77 ERA but a stunning 31 strikeouts in 14 1/3 innings. He moved up to the Winston-Salem Warthogs and was 2-0 with 2 saves, a 4.38 ERA and 15 strikeouts in 12 1/3 innings. Returning to Winston-Salem in 2001, Jeff went 2-4 with 10 saves and a 3.35 ERA, striking out 51 in 40 1/3 innings. In two games with the Birmingham Barons, he fanned 5 in 4 innings and allowed no runs but 7 baserunners. He missed the whole 2002 season recovering from Tommy John surgery, returning in 2003 with a 4-2 record with 14 saves and a 3.20 ERA in Birmingham.
He began the 2004 season with the Charlotte Knights (1-2, 10 saves, 1.80) before being called up to the majors in September. In 2005, he was again at Charlotte, and made the Triple A All-Star Game. He had a fine 4-6, 19 saves, 1.41 season, striking out 83 in 70 1/3 innings while allowing only 45 hits. Lefties hit .301 against him while right-handers managed just a .125 mark. He was called up by the White Sox again late in the season. In 12 2/3 innings in the majors, he had 11 strikeouts. In his first two big-league trials, he had a whopping 9.24 ERA, allowing 19 hits and 13 runs. Before the 2006 season, the White Sox traded Jeff to the Arizona Diamondbacks for Alex Cintron. He spent most of the year with the Tucson Sidewinders, where he had a record of 4-4, 4.50 with 7 saves in 52 games. He also made his final major league appearance that season, giving up 4 runs in 1 inning to end with a career ERA of 36.00. He missed the entirety of 2007 and retired in 2008 with two shoulder surgeries under his belt.
In 2010, Bajenaru was hired as a pitching coach at Riverside Community College for 2011. Months later, he was hired on as pitching coach for the AZL Diamondbacks for 2011-2013. He then coached the Missoula Osprey in 2014-2015, Visalia Rawhide in 2016-2018, and Reno Aces in 2019. He was scheduled to return to Reno in 2020 before the season was cancelled due to Covid-19 then did coach Reno in 2021.
Beginning in 2005, Bajenaru was a member of SABR, one of the rare active players to have been a member of the organization.