DENVER — The Red Sox initially planned to start Jake Peavy against the Colorado Rockies Tuesday night and have John Lackey pitch just an inning or two Wednesday.
Then the advantages gained by finishing with the top record in the American League were deemed significant enough to change that thinking. So Lackey started on regular rest Tuesday and now Peavy will pitch Wednesday.
The idea had merit. Lackey pitched seven strong innings to beat the Rockies in June and has been dominant in interleague games throughout his career.
But the down-and-out Rockies foiled that, beating the Red Sox, 8-3, at Coors Field. They belted three homers off Lackey then piled on against the bullpen.
“Not our best night from the mound,” Sox manager John Farrell said.
Given the circumstances and the competition, it was a poor effort by the Red Sox.
The Rockies (72-86) are one of the worst teams in the National League and were 4-14 in interleague games. Tyler Chatwood, who hadn’t won a major league game since July, combined with three relievers to hold the Sox to seven hits.
Three of the hits came in the ninth inning, one a two-run homer by Jarrod Saltalamacchia.
The Sox (95-63) maintained a one-game lead on Oakland (94-64) for the best record in the league as the Angels beat the Athletics, 3-0.
The benefits of that status are significant.
The top seed will face the winner of the one-game wild-card playoff game on Oct. 2. The alternative is facing the Detroit Tigers, the likely No. 3 seed.
The top seed also gets home-field advantage throughout the postseason.
“By the way we play at home and the way our guys embrace our environment, it would be a very good thing,” Farrell said.
If the Sox and Athletics finish in a tie, the tiebreakers would go to Oakland.
The teams split six games this season, eliminating the first tiebreaker. The second tiebreaker is intradivision play, which would end up with a tie if the teams have the same overall record.
The third tiebreaker would be overall intraleague record. That also would be tied if the teams have the same record.
The fourth tiebreaker, and the deciding one, would be the second-half intraleague record. The A’s are 42-25 and the Sox 39-30.
Farrell hopes it doesn’t come to that.
“We’re also in a position where we control our own destiny,” he said.
Lackey (10-13) allowed four runs on six hits over six innings. The three home runs matched his most in a game this season.
Charlie Blackmon led off the bottom of the first inning with a home run to right field, his sixth of the season. With two outs, Michael Cuddyer lined a ball to right field that backed Shane Victorino up to the warning track. He had a play on the ball but it ticked off his glove for a double.
Todd Helton, who is retiring after 17 seasons and will play his final home game Wednesday, ripped the next pitch into left field for an RBI single.
Troy Tulowitzki (third inning to center) and Corey Dickerson (fourth inning to right) added solo home runs as the Rockies took a 4-0 lead.
Lackey has a 4.48 earned run average on the road this season, 2.47 at Fenway Park. If he starts Game 2 of the division series, that will be a major factor.
“I’ve probably given up a couple less runs than tonight if I was at Fenway,” Lackey said. “But I don’t know. If I could pitch that well on the road, I’d certainly try to.”
Chatwood was working on a two-hit shutout with two outs in the seventh inning when Will Middlebrooks doubled to right field.
Jackie Bradley Jr. followed with a hard-hit grounder to first base that Helton stopped with a dive. His flip to Chatwood was accurate but the pitcher dropped the ball.
Middlebrooks, running hard with two outs, headed for the plate. Chatwood then committed a second error by throwing the ball into the Red Sox dugout.
Bradley was awarded third on the error. Mike Carp pinch hit for Lackey. The 2-and-2 pitch from Chatwood got past catcher Jordan Pacheco and Bradley broke for the plate.
The ball caromed hard off the backstop, right back to the catcher. Pacheco got the ball to Chatwood and Bradley was out to end the inning.
Trailing, 4-1, the Sox started the bottom of the inning with rookie lefthander Drake Britton on the mound. Pacheco doubled to left field.
In came rookie righthander Brandon Workman for his first appearance in a week. Pinch hitter Josh Rutledge singled to right before Workman walked Blackmon to load the bases.
D.J. LeMahieu followed with a two-run single to center. After an uncontested double steal, Cuddyer had a broken-bat two-run single to right and the Sox were down, 8-1.
“We let that game get away from us,” Farrell said.
Workman had thrown 141⅔ innings this season and the Sox gave him a rest. In the long run, that could work out well. But on Tuesday it clearly hurt him.
“My command wasn’t very good at all tonight,” Workman said. “That’s something I can obviously work on. I wasn’t very sharp tonight.”Peter Abraham can be reached at email@example.com. Follow him on Twitter @PeteAbe.