Toronto @ Boston preview

Last Meeting ( Jul 21, 2012 ) Toronto 7, Boston 3

A visit from the banged-up Toronto Blue Jays wasn't supposed to be this taxing for the Boston Red Sox. Toronto has won the first two games of the series in convincing fashion and will be looking for a sweep as the set concludes Sunday afternoon at historic Fenway Park. The Red Sox haven't been swept at home by the Blue Jays since Sept. 28-30, 2009, but to avoid that fate they'll need a strong performance from struggling left-hander Jon Lester.

One of the most consistent starters in baseball coming into the season, Lester has had a dismal campaign - and is becoming agitated. "It's frustrating showing up every day busting my (butt) and going out there busting my (butt) when I pitch and just not pitching well," he told the team's official website. Lester will be opposed by Toronto right-hander Henderson Alvarez, who is having his own troubles in 2012 but has fared better of late.

TV: 1:35 p.m. ET, RSN (Toronto), NESN (Boston)

PITCHING MATCHUP: Blue Jays RH Henderson Alvarez (5-7, 4.29 ERA) vs. Red Sox LH Jon Lester (5-7, 4.80)

Since going 0-4 in a seven-start stretch earlier in the season, Alvarez has begun to right the ship. He's 2-1 in his last four outings, including a six-inning performance against the Yankees last time out that saw him allow just two runs on four hits. Alvarez has a win, a loss and a no-decision in three starts against the Red Sox this season. He last faced them June 25 at Fenway Park, escaping with the victory despite allowing five runs in five innings.

Lester appears to have reached his breaking point after getting tagged for six runs on seven hits in four miserable innings against the Chicago White Sox five days ago. The 28-year-old southpaw has just two victories in his last 10 games, but one of those came June 27 against Toronto. Lester is getting hit as hard as he has since his rookie campaign - opponents are batting .282 against him for the season, more than 30 points higher than his career mark.

WALK-OFFS

1. Lester is 81-41 in his career, giving him a 66.39-percent win rate. That's good for second among active players with a minimum of 1,000 innings pitched, behind only Philadelphia Phillies ace Roy Halladay (66.44).

2. The Red Sox are just 1-for-13 with runners in scoring position in the series.

3. Boston leaves town following Sunday's series finale to begin a pivotal six-game road trip against AL powerhouses Texas and New York.