ARLINGTON -- Clay Buchholz (13-5) is still within range of a 20-win season with likely nine starts remaining in the Red Sox's final 43 games.

Buchholz, who has won eight of his last 12 starts heading into Tuesday's game vs. Angels at Fenway Park, said 20 wins isn't anywhere on his radar at this point.

"I'm definitely not going to set any goals right now at this point in the season. It would be awesome," Buchholz said. "But the wins, you get lucky sometimes and give up five or six runs and still win a game.

"I don't think the wins are a really big deal," Buchholz said. "It's a matter of keeping the team in the game while I am out there pitching."

Kalish makes first start in center field

ARLINGTON -- The Red Sox were looking for a chance to play rookie Ryan Kalish in center field, and manager Terry Francona figured Sunday was a pretty good day to do it.

With Jacoby Ellsbury on the 15-day disabled list with his recurring rib injury -- and with 43 games left after Sunday, maybe done for the season -- the Red Sox need to figure out what to do about center field. Kalish, who Francona said is a solid outfielder, was in center field with Darnell McDonald, who played there Saturday, in left field. McDonald has started 39 games in the Red Sox's revolving door center-field position.

"We have some decisions to make coming up here about who plays, when they play, where," Francona said. "If he can handle this like we think he can, that tends to make us a little bit better."

Francona said Kalish has the ability to play all three positions. He gets high marks for paying attention, listening, being coachable and runs well enough to play center.

"He's probably not a burner, but he has good speed," Francona said. "He sort of has that nose for the ball, where you put a glove on him and he can kind of smell it. You get more out of him. That's probably not a very good explanation, but he kind of has a nose for the ball."

Is Ellsbury's season over?

"Well, [he's] not [going to play] for two weeks," Francona said. "We have to finish these next two weeks, and I don't know after. We have 13 games."

Lowrie battling aftereffects of heat exhaustion

ARLINGTON -- Shortstop Jed Lowrie was held out of the starting lineup on Sunday, less than 48 hours after leaving Friday night's game in the ninth inning because of heat exhaustion.

Manager Terry Francona said Lowrie woke up Sunday morning not feeling well. Lowrie did rally a little bit once he got to Rangers Ballpark, but that he felt "light-headed" after taking batting practice. Francona said Lowrie swung the bat "OK."

"The hard thing for me is that if you make him available and he can't stay in the game," Francona said. "We'll see."

Francona was asked if Lowrie's bout with mononucleosis for most of the season could be impacting his tolerance of the hot conditions in Texas. All three games have been played in 100-plus degree weather."

"That would make common sense," Francona said. "I don't know that anybody has said that, but I would assume, yeah."

Francona spent two years as a coach in Texas and said he did get used to the hot summers.

"I'd go home at night and I'd get tired, but I like it," Francona said. "It's like playing in the cold. These guys get used to it. It's different."

Worth noting

Reliever Hideki Okajima (right hamstring strain) threw 35 pitches in a bullpen session Sunday. He'll throw Tuesday, Thursday and the Rex Sox will decide the next step after that. ... Injured catcher Jason Varitek (right foot fracture) caught Okajima's bullpen session, which manager Terry Francona said was a good sign. Varitek is still at least seven to 10 days away from returning. ... The reports on first baseman Carlos Delgado in Triple-A Pawtucket have been pretty good, Francona said. Delgado is trying to come back from hip surgery. "Pretty good at-bats," Francona said. "For the most part, it's been pretty positive." Delgado is still not expected to be a possibility for the Red Sox until the beginning of September.