6) Robb Nen (9.40)
Robb Nen played in 643 major league games over 10 innings, and was the last pitcher in 549 of them. He didn’t start a single game.
Nen made his major league debut with the Texas Rangers in 1993. In July, they traded him with Kurt Miller to the Florida Marlins for Cris Carpenter. Nen pitched in 15 games for the Fish, pitching to a 7.02 ERA in 33 1/3 innings. He only struck out 27 in 33 1/3 innings, so it kinda looks like he figured something out later. In fact, through the entire 1993 season, he struck out 6.3K/9 between the Rangers and the Marlins. He would never again finish under 9.3K/9.
In 1994, Nen racked up a 2.95 ERA in 58 innings, saving 15 games and striking out 60 in 58 innings. Batters earned a 1.086 WHIP off him, and slashed just .222/.280/.382. Nen was 0-7 in 1995, but also saved 23 games and had a 3.29 ERA. He struck out 68 in 65 2/3 innings, finishing with a 1.294 WHIP.
In 1996, Nen was 5-1 with a 1.95 ERA and a 1.060 WHIP, with 35 saves. He struck out 92 in 83 innings, and held the opposing slashline down to .225/.277/.299. It was probably his best Florida Marlins season.
Nen went 9-3, 3.89 in 1997 for the eventual World Champions, and struck out 81 in 74 innings. His 1.514 WHIP would remain his worst full-season total through his entire career. After the season, the Marlins traded Nen to the San Francisco Giants for Mike Villano, Mike Pageler, and Joe Fontenot.