From there, the Tigers technically will have 10 days to try to trade Willis or see if another team claims him on waivers. Neither option seems likely.
With Willis all but certain to decline a Minor League assignment, this essentially means the end of a pairing that went perplexingly bad from the start in 2008, took an odd turn to the disabled list last year, then became an encouraging comeback story this spring. At no point, however, did Willis return to his younger form, when he was a 22-game winner and a World Series champion with the Florida Marlins.
"It never worked out the way we would've liked it to work out," team president/general manager Dave Dombrowski said in announcing the move. "I don't think I really need to say any more than that. At the time, we thought we were getting a guy who would come in and be a very solid big league pitcher, and it didn't work out for us. Those things happen at times. You're never happy when they do. He's put forward the effort. We know we've dealt with a lot of issues with him. It's unfortunate."
Willis was not available for comment after the game. Dombrowski said Willis took the news after the game "very quickly and shortly, and just said thank you and we thanked him. It was very short and simple."
Willis went 2-8 with a 6.86 ERA over the last three years with the Tigers, covering 24 games -- 22 of them starts. He missed stretches over the previous two seasons to the disabled list -- a knee injury in 2008, then what was termed as anxiety disorder last year -- but at the root, his Tigers tenure came down to a recurring battle with the strike zone and trying to find consistent command of his pitches.
The 28-year-old became a comeback story this spring when he won a job in the Opening Day rotation, beating out Nate Robertson and Armando Galarraga. Not only did his upbeat personality mesh well in a young Tigers clubhouse, he gave a positive review for Johnny Damon when he was considering signing with the Tigers in Spring Training, then became a mentor of sorts for rookie center fielder Austin Jackson.
For the season, he went 1-2 with a 4.98 ERA in eight starts and a relief appearance. He threw quality outings in three of his first four starts, including six scoreless innings with six strikeouts against the Twins in a big American League Central battle April 29 at Comerica Park.
It was his May struggles -- 0-1, 6.52 ERA, 23 hits and 17 walks over 19 1/3 innings -- that drew the Tigers to stick with the recently recalled Galarraga in the rotation over Willis. He had solid stretches in a couple of those May performances, retiring 11 of the first 12 Dodgers he faced May 21 in Los Angeles, but he had similarly rough stretches where he battled walks.
"I think probably the uncertainly is [the factor]," manager Jim Leyland said. "Not knowing what you were going to get was probably a key factor. I'll leave it at that, because he gave a great effort, and he was a great teammate. It's sad, really."
His performance Friday night against the A's, giving up three runs on nine hits with four walks and five strikeouts, prompted a meeting among club officials Saturday afternoon.
"It's difficult," Dombrowski said. "For us and for me, because we had a meeting with the staff members today, it's difficult, because he's worked hard to try to overcome a lot. He's made some strides, it became apparent, this year. For us, we just weren't seeing the same progress we saw in the spring. At times you see, but not on a consistent basis."
The question, Leyland repeated, came down to what club officials felt Willis could do going forward if he stayed in the rotation.
"This was based strictly and solely on the uncertainty that we felt like we had," Leyland said. "It really was a unanimous decision. Not one person makes that decision. We hashed it out and it was the uncertainty, not knowing for sure what you were going to get."
A disabled list stint was not an option. The Tigers apparently had no such discussions with either Willis or his agent, Matt Sosnick, until they informed Willis of the move Saturday night.
For now, Willis will be in roster limbo but would seemingly be headed for a release. Claiming Willis on waivers would involve taking on the rest of his contract. He is scheduled to make $12 million this season, the final year of the three-year, $29 million deal he signed with the Tigers after they acquired him from Florida in the Miguel Cabrera trade.
Even with the Tigers picking up the rest of that money, a little more than $8 million, it would appear questionable at best whether another team would give up a prospect for him in the way the Tigers were able to acquire a reliever from the Marlins for Nate Robertson at the end of Spring Training. Moreover, a team trading for Willis would have to put him in the big leagues right away.
With Willis all but certain to decline a Minor League assignment, as is his right, he could become a free agent in a week and a half, which would allow him to sign with another team for the Major League minimum and have the Tigers pick up the rest of his salary. More important for him at this stage, he'll get a fresh start in a new organization after trying everything he could in Detroit.
At least one teammate believes a fresh start can work.
"I definitely have seen some strides forward from last year to this year," catcher Gerald Laird. "He's close. He's going to bounce back and get with another club, and he's going to get right. It's tough to see a guy leave like that. But they felt like the decision needed to be made to better the ballclub, and they did it. It's one of those things you hate to see, but it's part of the game, and we all understand that. He does, too.
"His career is far from over. You are going to see him back somewhere."
Jason Beck is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.