Boston @ Colorado preview

Last Meeting ( Sep 24, 2013 ) Boston 3, Colorado 8

The Boston Red Sox hold a one-game lead over Oakland for the best record in the American League and home-field advantage in the playoffs. The Athletics own the tiebreaker should the teams finish in a tie, but the Red Sox could be getting reinforcements back in time for Wednesday's finale of a two-game series against the host Colorado Rockies. Center fielder Jacoby Ellsbury could be in the lineup for the first time since Sept. 6 and could be joined by first baseman Mike Napoli.

It will mark the final home game for Rockies first baseman Todd Helton, who is retiring after playing his entire 17-year career with Colorado. "I'll miss the anticipation of walking out of the tunnel and seeing the fans, and getting ready to play the game," Helton said. "That's going to be the toughest part to me." Charlie Blackmon is 22-for-44 during a nine-game hitting streak and Michael Cuddyer leads the National League with a .335 batting average.

TV: 8:40 p.m. ET, NESN (Boston), ROOT Sports (Colorado)

PITCHING MATCHUP: Red Sox RH Jake Peavy (11-5, 4.02 ERA) vs. Rockies RH Jhoulys Chacin (14-9, 3.21)

Peavy is unbeaten in his last six starts and had his third straight no-decision in his last outing, giving up three runs over seven innings against Baltimore. Although Peavy has been touched for 10 runs in the past three starts, he walked only one versus the Orioles after issuing eight free passes in his previous two turns. Peavy is 4-6 lifetime with a 3.92 against the Rockies.

Chacin, who will make the start in place of Roy Oswalt, beat Arizona in his last outing by giving up two hits in six innings, but he also walked a season-high five and failed to register a strikeout. Chacin has allowed more than three runs only twice in his last 14 starts, but both have come in his last four outings. He is 9-4 with a 3.77 in 17 home starts.

WALK-OFFS

1. Peavy is 3-4 with a 4.74 ERA in nine starts at Coors Field.

2. Chacin blanked the Red Sox on four hits over 6 2/3 innings in his lone career start against them in June 2010.

3. Boston has not lost its last 11 interleague series (9-0-2).

PREDICTION: Rockies 5, Red Sox 4