Ugueth Urbina: B-
Urbina didn't have a great season, as he had some occasional struggles as well as decrease in velocity on his fastball. But despite the occasional struggles, Urbina only blew 3 of the team's 28 blown saves, converting 21 of his 24 opportunities. He obviously lost the final part of his season because of the kidnapping, but assuming he wants to return to baseball, the Tigers will likely exercise their option on him to bring him back as the closer.
Jamie Walker: B
Walker got a lot put on his plate, largely due to the lack of reliable relievers the Tigers employed, and because of that he was at times overworked. Despite his occasional struggles, Walker still led the team in ERA at 3.20, while being relied upon as the setup man in many situations. It'd be a shock if he didn't return to the team in 2005.
Esteban Yan: C
Yan made the club as a minor league free agent, and performed fairly well when used as a long and middle reliever. However, Yan's struggles came to the forefront when he was shifted into the closer role when Urbina left the club. Of those 28 blown saves, Yan accounted for 10. Hard to say whether or not Yan will be brought back, although if he was, it'd certainly be as a latter member of the bullpen.
Al Levine: C-
Levine was signed in the offseason to give the Tigers a reliable late inning reliever, but Levine was rarely reliable. By the end of the year his ERA was back to a respectable level (4.58), but his performance wasn't nearly as good. It wouldn't be a shock if the Tigers let Levine go to look in a different direction for a better late inning reliever.
Danny Patterson: F
Patterson was hoping to return to his former role in 2004 as a setup man after losing most of 2 seasons with Tommy John surgery. Unfortunately, Patterson never appeared to be the same pitcher, and after being given some rest in hopes of reviving his arm, he still didn't come around, and was subsequently released.
Steve Colyer: D-
Colyer was acquired via trade just before the start of the season due to his live arm. Unfortunately, him being a lefty and throwing a mid to high 90's fastball wasn't enough to overcome his control issues. Colyer's ERA (6.47) and WHIP (1.78) were extremely poor. Colyer being a lefty and having great velocity on his fastball will afford him another chance – but he'll have to produce if he hopes to stick with the Tigers next year.
Craig Dingman: D+
Dingman was called up to Detroit in hopes of providing relief to the ailing bullpen, but Dingman wasn't much of an upgrade over what the team had from before. Dingman was already removed from the 40-man roster, and will not be expected to return to the team.
Roberto Novoa: C
Novoa was called up midseason from AA Erie, struggling some, but showing that he could be solid in relief as well. Novoa's K:BB ratio (2.5) and WHIP (1.47) were respectable, and his ERA was falling with a string of impressive performances down the stretch (he gave up just 1 run in 7 innings in his second call up). With a good spring, Novoa will be back with the club as a middle reliever.
Franklyn German: D
The enigma of the Tigers bullpen for parts of 3 seasons now, German is running out of chances. He has arguably the nastiest stuff of any member of the bullpen, but he has some sort of mental block that has yet to allow him to perform adequately at the major league level. Because of his stuff, he'll be given another chance in the spring, but he's likely out of them if he can't convert in his 4th chance.
John Ennis: D-
Ennis was another call-up from AAA Toledo, and similar to Dingman, struggled mightily in his appearances with the Tigers. Ennis was removed from the 40-man roster and declined his assignment, meaning he is likely done as a Tiger.
Fernando Rodney: Inc.
Rodney was originally expected to take over as the Tigers' closer, but the 27-year old ended up undergoing season-ending Tommy John surgery. Like German, Rodney has yet to really produce at the big league level, although he also has an impressive repertoire. If healthy, he'll be looked upon to be a solid setup man.
Chris Spurling: Inc.
Like Rodney, Spurling never made an appearance due to Tommy John surgery. However, he has begun throwing again and should be able to challenge for a spot as a middle reliever come spring, in hopes of building on his promising 2003 campaign.