ARLINGTON -- Injury-riddled Red Sox center fielder Jacoby Ellsbury was placed on the 15-day disabled list Saturday, his third DL stint of the season, once again because of a rib injury.

Ellsbury, who missed 95 games in two other DL stints this season, injured the area where he fractured five ribs in an April collision with third baseman Adrian Beltre. Ellsbury was injured Friday night in a first-inning collision with Rangers pitcher Tommy Hunter.

Ellsbury flew to Boston on Saturday morning for an MRI and a CT scan. Red Sox manager Terry Francona said the results showed some edema to the soft tissue in the same area, which is suggesting new trauma. He said there's a faint line at the fracture site, which could suggest incomplete healing.

"You just have to go on the symptoms and [Ellsbury] said it was worse than in Tampa, so we knew this was a DL [move]," Francona said. "So now that's he on the DL, we'll try to find out, 'What do we do?'"

Ellsbury went on the DL for the second time this season in May after feeling pain taking swings in the batting cage before a game in Tampa. He finally returned on Aug. 4 and had been struggling before turning things around a bit this week. He stole five bases in five games, including four Monday against the Yankees.

Francona said it wasn't known yet whether Ellsbury would fly to California to visit Dr. Lewis Yocum. When asked if this latest injury could end Ellsbury's already-shortened season, Francona said only that Ellsbury would be out for 15 days.

Francona said that Ellsbury fought to stay in Friday night's 10-9 loss to the Rangers.

"It was pretty obvious to me he was hurting," Francona said. "He didn't want to come out. I'm glad I took him out now. Obviously he was hurt. If he had gotten hurt worse, I mean, that doesn't help anybody."

Francona juggles options for center field

ARLINGTON -- The Red Sox will use a rotation of Eric Patterson, Darnell McDonald and even Ryan Kalish in center field with Jacoby Ellsbury going on the disabled list Saturday.

Patterson was in center field for Saturday's game at Texas.

Right-handed-hitting McDonald would seem to be the likely starter in center for Sunday's game with the Rangers starting left-hander C.J. Wilson (both Patterson and Kalish bat left-handed).

"It depends on who's available," manager Terry Francona said. "We'll see."

Lowrie rests after bout with heat exhaustion

ARLINGTON -- Red Sox manager Terry Francona said he would try to stay away from using Jed Lowrie for Saturday's night game after the shortstop suffered from heat exhaustion and was pulled out of Friday's game in the ninth inning.

Lowrie, who said he was feeling better before Saturday's game, said he was starting to feel "real dizzy" when he and the Red Sox's training staff decided that "enough was enough."

The game-time temperature in Texas was 99 degrees, but the heat index was well over 100. The Dallas-Fort Worth area has had 14 straight 100-degree days through Saturday.

Lowrie said the dizziness was the worst symptom he felt.

"My body temperature was pretty high," Lowrie said. "That's probably the main one. I was starting to get dizzy and felt like I wasn't going to be able to help on the field when I wasn't really seeing straight."

Lowrie said he had no idea what his body temperature was, but he could tell when he took his uniform off he was extremely hot. He said Friday night's weather conditions were the hottest of his professional career. Lowrie said he could feel it in his last at-bat against Darren Oliver.

"I felt like I was in a sauna really," Lowrie said. "It was kind of heavy."

Lowrie, who spent most of the season on the DL with mononucleosis, said he'd have to wait and see how he felt Saturday before knowing his availability for Sunday's series finale in Texas. Sunday's high is forecast for 104 degrees with a heat index between 108 and 112 degrees. The Red Sox are facing a tough left-hander in Rangers starter C.J. Wilson.

"The hope will be maybe he can play tomorrow," Francona said. "C.J. Wilson's a nice guy to have some righties in there. We'll just see. I don't think it's going to be 70 and breezy tomorrow."

Worth noting

Left-handed reliever Hideki Okajima (right hamstring strain) will throw bullpen sessions Sunday, Tuesday and Thursday and be re-evaluated after that. ... Manager Terry Francona said he was going to try to stay away from closer Jonathan Papelbon and setup man Daniel Bard for Saturday's game because they both had pitched consecutive days. Francona said he wanted to see reliever Felix Doubront in back-to-back games.