Jon Lester and Ricky Romero each started the season at the top of his team's rotation, but the results haven't been ace material for either left-hander lately.

Thanks to Toronto's powerful lineup, that hasn't reflected in Romero's record.

Lester and the Boston Red Sox could be in for a rough finish to a solid homestand Wednesday if the Blue Jays continue to support Romero with runs in bunches.

Romero (8-1, 4.34 ERA) has allowed at least four runs in each of his last six starts, but he's 3-0 in that stretch because Toronto has averaged more than a run per inning with the southpaw on the mound.

"I've been lucky," Romero admitted after allowing four runs in seven innings of a 12-5 win at Miami.

"The hitters have done their part every time I've pitched it seems like.

"It's been a grind, it honestly has. Nothing has come easy for me this year.

"It's no secret. I'm battling, grinding and trying to do everything possible to get deep in the game."

The same could be said of Lester (4-5, 4.48), who has an ERA more than a run higher than any of his previous four seasons. Opponents have hit .311 against him over his last seven starts and he allowed 10 hits to Atlanta in Friday's 4-1 defeat.

Lester has been unable to explain why he's not having the success he's used to, and his frustration showed after his latest loss.

"I'm getting tired of the same old [stuff]," he said, using a profanity. "Making good pitches and they're getting hit.

"I don't know what else to do … Same book, different chapter for me."

Perhaps facing each other will get Lester and Romero going. They both were sharp in Toronto on April 11, each allowing just three hits with Romero pitching into the ninth inning of his 3-1 victory.

Despite that defeat, Lester is 4-1 with a 1.99 ERA in his last seven starts against the Blue Jays. After a brutal start to his career against the Red Sox, Romero has won three straight starts in this series.

The Red Sox, though, have been hitting the ball hard on this homestand, which they can finish at 7-2 with a victory Wednesday. They've averaged 7.1 runs in the first eight contests, breaking through for all of their scoring in the seventh and eighth innings of Tuesday's 5-1 win.

Jarrod Saltalamacchia hit his 14th homer, leading all major-league catchers, while Adrian Gonzalez and David Ortiz each doubled twice. Dustin Pedroia had the go-ahead two-run single in the seventh and is 7 for 14 with three walks in his last four games.

"I feel like, any given night, it's someone different," Red Sox shortstop Mike Aviles said. "Every night, you never know who's going to be the hero and that makes the game intriguing for us."

While the Red Sox (39-35) are trying to move five games over .500 for the first time this season, Toronto (38-36) is looking to pull back even with Boston at the bottom of the AL East.

The Blue Jays' bats went quiet Tuesday after hitting three homers in Monday's 9-6 win. Colby Rasmus finally cooled off, going 0-4 with two strikeouts after batting .410 with five homers and 15 runs batted in over his previous nine games.

Rasmus has never faced Lester, but the left-handed hitter has eight hits in his last 15 at-bats against lefties.

Catcher Kelly Shoppach often starts against southpaws for Boston and he'd figure to spell Saltalamacchia in a day game following a night contest, but he's 0 for 15 with six strikeouts against Romero.