While John Lackey has struggled of late for Boston, Seattle's Hisashi Iwakuma has shined for the Mariners since he was roughed up by the Red Sox earlier this month.
Lackey looks to avoid a third straight loss while trying to hand the All-Star and the Mariners an eighth consecutive defeat at Fenway Park on Wednesday night.
Though Boston (64-44) acquired veteran Jake Peavy from the Chicago White Sox on Tuesday as part of a three-team deal with Detroit, it likely can't afford Lackey (7-8, 3.19 ERA) to regress after his strong two-month stretch. The right-hander went 6-2 with a 2.32 ERA in his previous 11 starts before allowing nine runs and 19 hits over 12 2-3 innings in losing the last two.
Lackey gave up three homers and five runs overall in 6 1-3 innings of a 6-0 loss at Baltimore on Friday. His teammates, however, failed to score with him on the mound in both defeats.
"I felt OK, but they kind of took advantage of a couple of things," Lackey told the Red Sox's official website after his last outing. "I didn't pitch good enough."
Lackey hasn't faced the Mariners since 2011, but he's 4-1 with a 1.84 ERA in his last six against them.
Iwakuma (10-4, 2.87) yielded a season-high six runs and homers to Dustin Pedroia, David Ortiz and Mike Napoli in three innings but did not factor in the decision of an 11-8 loss to Boston on July 9. Since the shortest start of his career, the right-hander has posted a 2.25 ERA while winning three straight outings.
Iwakuma gave up four hits and struck out nine in six scoreless innings of an 8-2 win over Minnesota on Thursday.
"He did a great job of battling and working down in the zone," injured catcher Mike Zunino told the Mariners' official website. "The last few starts he's been really good at doing that."
Iwakuma hopes to help Seattle (50-56) end a seven-game skid at Fenway during which it's been outscored 44-18. The Mariners fanned 12 times, including nine against rookie Brandon Workman in Tuesday's 8-2 loss.
Pedroia homered and had three RBIs and Shane Victorino added three hits as a Boston bounced back after a blown call at the plate Monday overshadowed a 2-1 loss to Tampa Bay.
Boston trails the first-place Rays by one-half game in the AL East.
Pedroia was mired in a 2-for-35 slump heading into Tuesday's contest but is batting .407 (11 for 27) during Boston's home winning streak against the Mariners.
Victorino is 7 for 14 this season versus Seattle, which has lost four in a row overall against the Red Sox.
Kyle Seager and Kendrys Morales each had two hits for the Mariners, who have dropped four of six since a season-high eight-game winning streak.
"We had our backs up against the wall there early and were never able to make a run at it,'' said Robby Thompson, who is serving as acting manager while Eric Wedge recovers from a mild stroke.
Morales is batting .315 with 11 RBIs in 18 games.