But the 6-foot-6 right-hander attributed his poor outing to a different mindset, knowing this game was just a start to get ready for his more important outing next week.
"It's a little different because you don't know how far you're going to go," Lackey said. "But obviously, you want to do better than that, but it's a different feel. They kind of beat me up tonight."
The loss was essentially meaningless, though, as it came after the Angels had already clinched home-field advantage and the best record in baseball for the first time in club history after the Rays lost to the Tigers earlier Friday.
Lackey allowed the 10 runs on 12 hits over just 2 2/3 innings to fall to 10-10 with a 5.72 ERA against the Rangers in 27 career starts. But he was coming off a solid start in Texas last week, where he allowed no runs and just two hits over six innings.
"It was 180 degrees from what John pitched last week in Texas," manager Mike Scioscia said. "He struck out 12 guys and looked sharp in Texas. Today, it seems like they squared up everything he threw out there. But he'll turn the page."
After allowing a run in the first inning, Lackey allowed seven runs in the second -- much to the dismay of the sellout crowd of 43,758 at Angel Stadium.
He opened the second frame by allowing six consecutive hits, including a solo home run by Hank Blalock, before hitting Josh Hamilton to end the hit streak. Lackey allowed seven hits, a walk and a hit batsman in the inning while throwing 41 pitches to 12 batters.
Lackey allowed another two runs in the third, including a solo home run by Hamilton, before being relieved by Shane Loux with two outs in the inning. Loux allowed two runs over 3 1/3 innings before being relieved by Jason Bulger, who pitched the last three innings of the game without allowing a run.
Even though the Rangers got to Lackey on Friday, Texas' players felt it wasn't indicative of the way he usually pitches.
"The start at our place [on Sunday] was the best I've ever seen him," said Blalock, who went 2-for-5 with a home run and two runs scored. "Today was just a rough outing. He's still their No. 1 starter and a horse. I'm sure he'll be back."
The Angels' offense, meanwhile, was held in check by Vicente Padilla, who allowed a run in the first on an RBI single by Vladimir Guerrero before settling down. Padilla allowed just one run on four hits over six innings to earn the victory.
But Padilla's success mostly came against the Angels' backup players, as Los Angeles substituted out every position player except for Juan Rivera after the third inning when it was already down, 10-1.
The move was done mostly because of a late flight back from Seattle after Thursday's game, and because the game had no bearing on home-field advantage in the playoffs.
"I think that getting here at 4 in the morning, it was good to get those guys loose and in the flow, but we didn't really need to push them tonight," Scioscia said.
The backups didn't fare well, as Robb Quinlan and Reggie Willits were the only substitutes to get a hit against the Rangers. The Angels didn't threaten to score again until the bottom of the ninth, when they loaded the bases after three consecutive walks before Matt Brown and Bobby Wilson flied out and popped out, respectively, to end the game.
The loss kept Los Angeles at 99 wins, though the club has a chance to break the club record with No. 100 over the final two games against Texas. The Angels, though, are expected to rest players because their last goal has already been accomplished.
"We're going to go out there and win every game we play, but some guys need to get off the field a little bit," Scioscia said. "If we do get to the 100th win, it would be a nice milestone, but getting home-field advantage was much more important. So we're there now, and there's not much left to accomplish in the regular season."