OAKLAND -- Having already dueled Justin Verlander once this postseason, A's rookie Sonny Gray knew that Game 5 could be decided by just one mistake.

"And I was the one who made it," Gray said. "Not him."

Gray's fateful misfire Thursday was a fastball that Miguel Cabrera belted for a two-run homer in the fourth inning. The blast propelled the Detroit Tigers to a 3-0 victory that wrapped up the American League Division Series.

Overall, Gray was just wobbly enough -- three earned runs over five innings -- to raise the question of whether A's manager Bob Melvin made a mistake, too, in choosing the 23-year-old Gray over staff ace Bartolo Colon, who was 18-6 with a 2.65 ERA during the regular season.

There was no such second-guessing in the A's clubhouse.

"Sonny was outstanding tonight, absolutely outstanding," catcher Stephen Vogt said. "He gave us a chance to win, and we didn't get it done."

"At the end of the day, he basically just gives up a home run to Miguel Cabrera," Melvin said. "When he did get in jams, he ended up making pitches to get himself out of it. He pitched fine tonight."

Gray got the nod over Colon in part because of his sizzling outing Saturday, when he pitched eight shutout innings in the A's 1-0 victory. But by his own admission, he wasn't the same guy this time out, even before suffering an apparent broken left thumb on Prince Fielder's hard comebacker to end the fifth.

"Obviously, I wasn't as smooth," said Gray, who is headed for an MRI exam Friday. "Fastball command, as a starting pitcher, is a key for every game and tonight, I was just up. I was 1-0, 2-0 a lot, and you just can't do that. Eventually it's going to come back to hurt you, and tonight it did."

In his quest to get the feel for his fastball, Gray put his curveball on the back burner, too. The rookie said his dastardly breaking pitch works best when he can set it up with the proper pitch sequence.

"I took (the curve) out of play myself just because the reactions are going to be different if I'm not throwing strikes with my fastball," he said.

The fastball, however, did him in. With Torii Hunter on first and one out in the Tigers fourth, the A's expected Cabrera to be leaning over the plate in anticipation of a pitch on the outside corner.

Vogt called for an inside fastball, but Gray didn't bury it deep enough. The pitch drifted over the heart of the plate.

"You can't do that," the rookie said.

The two-run shot was Cabrera's only home run of the series. And it owed at least a little bit to the scouting report the Tigers put together after Gray bamboozled them in Game 2.

"To me, he's a great pitcher," the Detroit slugger said. "The first time we saw him, he pitched an excellent game. Today, we were able to be patient, try not to make mistakes and tried to wait and swing at our pitch. ... We had a different plan."

Colon, meanwhile, was reduced to a "what if." Maybe he could have matched zeros with Verlander a little longer? Maybe it would have been worse? (Colon hadn't beaten the Tigers since April 13, 2003, and was 0-8 in 14 starts against them since.)

Or maybe, on a night when Verlander was at the top of his game, the question had no right answer.

"When you don't score a run and only get a couple of hits," Melvin said, "you have to be perfect."

Follow Daniel Brown on Twitter at twitter.com/mercbrownie.