The right-hander was shelled Thursday, giving up seven runs on seven hits in 2 2/3 innings in a loss to the Indians.
Beckett was already in hot water with Red Sox fans after reports circulated earlier in the week that he went golfing on a team off-day just one day after the club announced he would miss his upcoming start with right lat stiffness. And he did little to quell the fans' frustration.
"I spend my off-days the way I want to spend them. My off-day is my off-day," Beckett said after his start May 10, his shortest outing since 2008. "We get 18 off-days a year. I think we deserve a little bit of time to ourselves."
The Red Sox have won four in a row since Beckett last pitched, and manager Bobby Valentine believes the right-hander has put the poor reception behind him.
"I certainly hope so," Valentine said. "He seems very relaxed."
The club also looked into the possibility that Beckett was tipping pitches. He is 2-4 with a 5.96 ERA in six starts this season.
"There has been a video analysis," Valentine said. "I'd rather not say what was being looked at or what was found. We've got other people looking."
The Red Sox beat the Mariners, 6-1, on Monday to improve to 8-11 at Fenway Park this year. Boston's four-game win streak at home is the team's longest this season. The Sox have won their last five games against the Mariners at Fenway and Seattle is 1-9 in its last 10 on the road.
Blake Beavan starts for Seattle after getting his turn pushed back two days with a bruised right elbow. He was hit in the elbow by a line drive off the bat of Detroit's Miguel Cabrera on May 7.
Beavan threw a bullpen session on Sunday and was pronounced ready to go.
"It's still a little tender on the bone, but nothing holding me back as far as delivery or throwing or finishing my pitches," the right-hander said.
The second-year starter pitched once at Fenway Park last year, also against Beckett, and said he enjoys the ballpark's history and atmosphere.
"It'll be fun to pitch there again," Beavan said. "It's that kind of place, with the history and everything. You can't say how many times you'll get to see a game there, let alone pitch or play in one."
Beavan is 1-3 with a 4.32 ERA in six starts this year.
Mariners: Ackley on a roll
Dustin Ackley extended his hit streak to 10 games with a single in the sixth inning Monday. It's the longest steak of the season for the Mariners.
The second baseman finished the night 1-for-4.
Ackley is batting .367 (22-for-60) with 13 runs scored, four doubles and eight RBIs in Seattle's 15 wins when he's in the lineup. Conversely, Ackley is batting .160 (13-for-81) with five runs scored, three doubles and two RBIs in the club's 20 losses when he starts.
The Mariners are 6-6 in the 12 games Ackley bats leadoff, including Monday's loss. Seattle is 9-14 when he bats second.
Red Sox: Nava making most of second chance
Daniel Nava is back in the Majors and making a case to remain in the Red Sox's lineup.
The outfielder belted a two-run home run over the Green Monster in the fourth inning Monday. It was Nava's first big league homer since a first-pitch grand slam in his Major League debut on June 12, 2010.
Nava has started all five games in left field since being recalled from Triple-A Pawtucket on Thursday and is 7-for-12 with six RBIs. He's reached base at least three times in four games. Nava did not play in the Majors last season after appearing in 60 games in 2010.
"I think just getting to do it that second time around helps me understand how to go about my business and what to expect," Nava said. "Any time you do something a second time around, there's a comfort factor. That's helpful."
Boston is 4-1 since recalling Nava.
Seattle reliever Lucas Luetge has not allowed an earned run in his first 14 Major League appearances.
Boston is 4-10 in day games.
The Red Sox have outscored opponents 29-8 during their four-game win streak.