Beckett returns from a brief bout with back spasms Wednesday to face Harrison as the Red Sox and Rangers finish their season series at Fenway Park.
The last time Beckett (5-9, 4.54 ERA) was on the mound, he walked in a run and was removed from a July 31 game against Detroit in the third inning after his back tightened up on a soggy mound.
Even while injured, he heard some boos as he departed, likely due to his recent performances -- he's 1-5 with a 4.94 ERA in his last nine starts, with Boston going 2-7 in those games -- combined with lingering memories of his role in last season's epic September collapse.
Beckett said he's not fazed by the reaction of the fans and media.
"I think for me, I'm just me," Beckett said Tuesday in an appearance on Boston radio station WAAF. "I don't pay too much mind to when people have their opinions about it. I'm not going to change and I think sometimes that's kind of what the media outlets want you to do here."
After dealing with trade rumors leading up to the deadline, Beckett said he's happy in Boston and that the Red Sox clubhouse is the "exact opposite" of the dysfunctional place it's been reported to be.
Beckett has lost both of his starts against the Rangers this year, allowing seven runs in 14 innings, but may find reason for optimism in his most recent outing. He retired the first eight batters he faced against the Tigers before unraveling.
Harrison's last start produced his 13th victory, and he needs only one more to match his career-high total from last season. The left-hander allowed two runs and eight hits over 6 2/3 innings of a 5-3 win Friday at Kansas City.
He had given up nine runs over 13 innings while losing his previous two outings.
"He's got a mean streak now," manager Ron Washington said. "That mean streak grew into him. He didn't always have it. He hates to be taken out of the game. He hates when he doesn't go out there and do good."
Harrison (13-6, 3.17) hasn't faced Boston this year, but he did very well at Fenway last season, yielding two runs in seven innings of an 11-4 win Sept. 4. He leads the majors with nine road wins this year, posting a 2.99 ERA in 12 starts outside of Arlington.
He'll be looking to follow a strong outing by new teammate Ryan Dempster, who took a shutout into the seventh inning of a 6-3 win Tuesday. The Rangers, who lost 9-2 on Monday, clinched their fourth straight season-series victory against Boston.
"It was a good bounce-back win after last night," Washington told his team's official website. "It was certainly a big game. We didn't want to go down 0-2. Now we tied the series and have a chance to win it."
Texas is 24-12 against the Red Sox since 2009, and has outscored them 47-24 while winning five of seven meetings this year.
Boston (55-56) can't seem to harness any momentum and is now trying to salvage a split of its 10-game homestand. The Red Sox begin a 10-game road trip Thursday in Cleveland.
Dustin Pedroia won't have long to cool down after getting ejected in the ninth inning Tuesday. He had been called out on a questionable check swing in the bottom of the eighth.