Walker was outstanding, especially against left-handed hitters, and his departure leaves the Tigers bullpen with a left-handed deficit that must be filled.
Or does it?
Though the returning bullpen cast is predominantly right-handed, the caliber of that talent is such that the loss of Walker may not be felt as keenly as first anticipated for a Detroit pitching staff that led the Major Leagues last year with a 3.84 ERA.
One of the keys will be the performance of right-handers like Jose Mesa and Jason Grilli.
Mesa's arrival gives Tigers manager Jim Leyland another late-inning option, along with Fernando Rodney and Joel Zumaya, in front of closer Todd Jones.
"That's one of the reasons [Mesa] is here -- he's a nice fit for us and he can pitch that seventh or eighth inning if one of both of those guys need a day off," Leyland said. "[He's] certainly got a pretty good track record."
Mesa went 1-5 with a save and a 3.86 ERA in 79 games for Colorado last season. In 72 1/3 innings, the right-hander gave up 73 hits and walked 36 while striking out 39.
Mesa fared as well against left-handed batters as he did against right-handers last season, holding both to a .270 average. A lighter workload in a more pitcher-friendly park should also benefit Mesa, who held lefty hitters to a .243 average before the All-Star break last year and .304 the rest of the way.
Mesa, who will turn 41 in May, has 320 career saves.
Lefty batters hit .292 off Grilli, but the right-hander improved his success rate against them as the season progressed. Lefties hit .357 off Grilli in the first half, but only .243 the rest of the way, even though Grilli faced more left-handed batters in the second half.
And of course Zumaya, Rodney and Jones are back, and Wilfredo Ledezma, a lefty who can start, might also be available to help fill the void created by Walker's departure.
"We've got some pretty good arms down there, along with some experience," Leyland said. "Our bullpen is really important to us. It's probably true with everybody now, but most teams don't have horses to pitch eight innings. That's why our bullpen is so important. Some of them aren't eight-inning pitchers -- that's just the way it goes."
Sleeth's curveball returns: Kyle Sleeth, the Tigers' third pick in the 2003 First-Year Player Draft, has rediscovered his curveball.
"Going through the Tommy John surgery [in 2005], I really lost the feel for my curveball, so I canned my curveball for about a year and a half," Sleeth said. "I started throwing it again recently, and once I started to get it back, it kind of came back right away."
Sleeth says he's throwing his fastball, changeup, slider and curveball with an arm that feels better than it has in more than two years. He's also completely healthy.
"He's not going to be on the club this spring, but he's a very interesting guy, because, from what I've seen, his stuff is very very good," Leyland said of Sleeth. "I'm not that smart, but just from what I've seen, he's without question a prospect and a very good one. [He's] definitely healthy, throwing extremely well, got a nasty breaking ball -- that's pretty much all you can take at this point."
Game time: Starting Tuesday, the Tigers will begin a stretch in which they'll play 32 games over 33 days, with an off-day on March 21 being the only break in the string.
Detroit will host Florida Southern College in a 1:05 p.m. ET game at Joker Marchant Stadium on Tuesday, with right-hander Virgil Vasquez, who looked impressive in the Arizona Fall League, scheduled to start for the Tigers. Jones, Sleeth, Ledezma, Edward Campusano, Mesa and Jair Jurrjens will also be available to pitch.
Volunteers sought: Leyland strolled through the Tigers clubhouse early Monday morning calling for volunteers. His plea prompted a few chuckles.
"Anybody want to go to Port St. Lucie?" Leyland said. "Raise your hands! Any volunteers to go to Port Lucie?"
No one raised his hand for the two-and-a-half-hour drive to New York Mets camp, where the Tigers will play their Grapefruit League opener on Wednesday afternoon.
Right-hander Chad Durbin will start against New York and left-hander Oliver Perez. Zach Miner, Andrew Miller, Bobby Seay, Preston Larrison and Felix Heredia will also be available to pitch for the Tigers.
A simple plan: Leyland has three goals for each Spring Training, and this year is no different.
"No. 1 is to get the Major League club ready for the regular season," Leyland said. "No. 2 is try to play .500 so the fans don't panic, and No. 3 is look at as many kids as you can."
Leyland said the latter two, however, are a distant second, and third behind the priority.
Quotable: "Just gotta show up. Let me just put it this way -- with the job that he did last year, he's on the club unless something crazy would happen." -- Leyland, on what Grilli needs to do to make the team
Rotation set: Leyland has set the probable starters for the rest of the opening week of the Grapefruit League schedule.
Mike Maroth will start on Thursday against Philadelphia at Joker Marchant Stadium. Jeremy Bonderman will face the Houston Astros at Kissimmee on Friday, and Nate Robertson will pitch against Cleveland on Saturday in Lakeland.
Kenny Rogers is the scheduled starter for Sunday's game at Winter Haven against the Indians, and Justin Verlander will make his first start of the spring on March 5 against the New York Yankees at Tampa. The Tigers will return to Lakeland on March 6, when Maroth will go to the mound for a game against the Toronto Blue Jays.
Jim Molony is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.