DETROIT -- Jarrod Washburn couldn't have expected his new home to be a destination city in late summer. But he couldn't have expected it to be this rough of a welcome.

Five home starts into his stretch run with the Tigers, he's still looking for his first win at Comerica Park in a home uniform. But then, 25 pitches into his latest outing Monday afternoon, he was still looking to retire his first Tampa Bay Ray, and struggling to avoid frustration.

"If you get frustrated and you let it get to you, then it really blows up," Washburn said after the Tigers' 11-7 defeat. "I don't know if it could've blown up any more than it did on me. Six runs in an inning, you're not going to win too many games when you put a team in a hole like that."

All six of those runs came in the first six batters. He went on to retire nine in a row after that with what he said was the same stuff he took into the opening inning. All he and the rest of the Tigers could do is shake their heads.

That's all Washburn can do about the past month since coming to the Tigers. Asked to assess his time so far, he was bluntly critical of himself.

"I would say pretty terrible," he said. "I've had a bad month. The whole month I've been here, I've had a good couple good starts, but overall, I've been not good."

His pitches weren't that bad. The results were his worst not only since joining the Tigers, but his worst to open a game since he got to the big leagues.

Carlos Pena's 38th home run of the year started him on his way to a three-hit, four-RBI day at his old home park, but it closed out the roll of six straight Rays to reach base safely. It was also the only truly hard-hit ball of the bunch.

The last four hits went for extra bases, including three straight RBI doubles. A down-and-in fastball to Ben Zobrist ended up laced into left-center to open the scoring, but Washburn recovered from that to put Pat Burrell in an 0-2 hole. He tried to get Burrell to chase a ball off the plate, then had to watch in wonder as Burrell reached and poked a blooper down the right-field line.

"It was a changeup about a foot off the plate," said catcher Alex Avila, still impressed that Burrell got it.

Avila was just as impressed with what Evan Longoria did with a fastball meant to jam him inside. He laced that one down the right-field line as Burrell came around to score for a 3-0 lead.

Up came Pena, batting under .200 against left-handed pitchers, and facing a starter who had been holding left-handed hitters to a .173 average entering Monday. Yet, when Washburn tried to start him off with a fastball on the outer half, Pena sent it out to right.

Pena's ex-teammate, Carlos Guillen, cut into the deficit with his two-run homer in the bottom of the inning, but four runs is as close as the Tigers came the rest of the afternoon.

"There was a point," manager Jim Leyland said, "where they had six runs, we had two, and we might've hit the ball harder than they did, with the exception of Pena's home run."

The quality of contact doesn't factor into the statistics on Washburn. He joined the Tigers with a 2.64 ERA on the season, third-lowest in the American League. Monday's loss raised it to 3.55. He has allowed 28 runs on 41 hits over 37 innings since joining the Tigers, including 25 runs over five home starts. His only win as a Tiger came on the road last week against the Angels.

"Anytime you get traded to a team that's in first place and has a chance to go to the playoffs, you want to do what you can to help them get there," Washburn said. "And I haven't been helping."

When asked if he's concerned, Leyland agreed. He isn't overly worried, he said, but he isn't ignoring it, either.

"Sure, I'm concerned," Leyland said. "He's given up quite a few runs in several of his starts now."

Yet as Leyland also pointed out, the add-on runs mathematically made the difference in the game, from Jason Bartlett's sixth-inning solo homer that helped chase Washburn from the game to Pena's fifth-inning RBI double and seventh-inning RBI single.

Between Washburn's struggles and Aubrey Huff's slump at the plate, the biggest contribution from a summer acquisition so far has been Guillen, whose four-hit game Monday included two homers to give him eight in 5 1/2 weeks since coming back from the DL.