Jon Lester surrendered five earned runs over five innings Sunday in Boston's loss to the Orioles.

The collapse continues for Lester, who started the season strong but has been knocked around in six straight outings. He had a 2.73 ERA after his May 10 shutout against the Blue Jays and it's now 4.37. The left-hander should be on fantasy benches next time out when he faces a dangerous Tigers offense at Comerica Park.

Jon Lester will start Sunday against the Orioles.

Clay Buchholz (neck) was originally hoping to start Sunday, but he's now aiming for Tuesday. Lester owns a 6.90 ERA over his last five starts, but insists that his recent struggles have more to do with his mechanics than his health.

Jon Lester said after Tuesday's start that he feels healthy.

Lester walked a career-high seven and gave up seven runs in 4 2/3 innings Tuesday night against the Rays and owns a 6.90 ERA over his last five starts. His recent struggles have naturally led to questions about his health, but he says he's 100 percent. "No, I feel great," said Lester. "I honestly do. Probably the best I've felt all season. It just comes down to commanding the baseball. Command the baseball is simple, and I didn't do that." An explanation offered by Lester, manager John Farrell, and pitching coach Juan Nieves is that the southpaw has been unable to repeat his delivery and location with any of his pitches. It's something to monitor moving forward.

Jon Lester walked a career-high seven and allowed seven runs over 4 2/3 innings in Tuesday's loss to the Rays.

He gave up eight hits - including a trio of longballs - while striking out three. After a terrific start, Lester's ERA has gone from 2.72 to 4.12 over the last five outings. He has just one quality start over that stretch, and that was a six-inning, three-run showing. The left-hander will try to bounce back this weekend in a tough matchup in Baltimore.

Jon Lester served up a pair of home runs in Thursday's no-decision against the Rangers, allowing three runs on seven hits over his six frames.

Lester struck out four on the evening and walked three. Jeff Baker tagged him for a two-run shot in the second inning and Adrian Beltre added a solo blast in the third. After an outstanding start to the season, Lester is now winless in his last four starts. He'll look to get back on track when he does battle against the Rays in Tampa Bay on Tuesday.

Jon Lester yielded four runs in 6 1/3 inning Friday in a loss to the Yankees.

Lester gave up six hits and four walks in the loss. He has now allowed four runs or more in three straight starts, increasing his ERA from 2.72 to 3.53 in the process. He'll hope to buck that trend next week when he faces the Rangers.

Jon Lester gave up four runs over seven innings in a no-decision against the Indians on Saturday.

Lester struck out eight and gave up a season-high 10 hits. He had a chance to get out of a jam in the top of the seventh inning, but threw a wild pitch with two outs to allow the go-ahead run to score. Fortunately for him, the Red Sox got him off the hook by scoring four runs in the bottom of the eighth. Lester will carry a fine 3.34 ERA into an interleague matchup against the Phillies next week.

Jon Lester yielded six runs -- five earned -- in six innings Monday against the White Sox to take his first loss of the season.

Lester, who entered 6-0, has always had problems with the White Sox. He's now 4-5 with a 5.43 ERA in 10 career starts against the team. He's 87-44 with a 3.64 ERA against everyone else.

Jon Lester allowed two runs over seven innings as the Red Sox defeated the Rays 9-2 on Wednesday.

The start came on the heels of Lester's one-hit gem against the Blue Jays his last time out. The southpaw wasn't quite up to that standard Wednesday, but he was still plenty good enough to get the win. He's now 6-0 with a 2.72 ERA and is enjoying a bounce-back campaign from his down 2012. His next start will come Monday against the White Sox.

Jon Lester tossed a one-hit shutout Friday in a 5-0 win over the Blue Jays.

It was his third career shutout and his 10th complete game. Lester faced one batter over the minimum, striking out five while walking none. The Blue Jays' only hit was a two-out double by Maicer Izturis in the sixth inning. Lester is now 5-0 on the year and holds an excellent 2.73 ERA and 45/15 K/BB ratio over 52 2/3 innings. He'll look to keep his bounce-back campaign rolling next week against the Rays.