ARLINGTON -- The Rangers placed outfielder Craig Gentry on the seven-day concussion disabled list Thursday because of a concussion that he suffered while sliding into second on Sunday.

"Today I actually feel pretty good," Gentry said. "The last two days, I've had headaches and felt a little nauseated, but today I woke up and felt pretty good, so we're moving in the right direction."

The Rangers are being cautious with Gentry because he has a history of concussions.

"That's why we're on the precautionary side -- this is my fourth or fifth concussion," Gentry said. "This is one of those things where the more you get, the easier it is to get them."

Because he was placed on the seven-day DL, it could not be retroactive to Monday, even though he had not played since then.

"We just want to make sure everything is right with him, he's too valuable for us," Rangers manager Ron Washington said.

In his place, the Rangers recalled Taylor Teagarden. This is Teagarden's fourth stint in Arlington, and he has hit .269 in 26 at-bats as a backup catcher. Washington thinks Teagarden can give him more flexibility to use Mike Napoli at spots other than catcher.

"It will give us the chance to get more out of Napoli and not have to worry about having a catcher in case something happens," Washington said. "It gives me more opportunity to do more things with Nap."

Prospect Martin leaves impression on Rangers

ARLINGTON -- Rangers outfield prospect Leonys Martin went back to Triple-A Round Rock after finishing his second day of workouts with first-base coach Gary Pettis on Wednesday.

He impressed Rangers manager Ron Washington with his talent and his ability to work.

"I didn't know where he was going to be, but I could tell you he is a talent," Washington said. "It is raw, he needs to play baseball and learn a lot, but he's got good aptitude. The kid works, and tries it. He swings the bat, he can run. The talent is there, it's just like any young kid."

Because Martin signed on May 4 -- during the season -- the Major League staff never got the chance to work with him. He was sent straight to extended spring training. He was put on the 40-man roster, so a September callup during roster expansion remains a possibility for Martin.

"He's learning," Washington said. "We brought him in here for one purpose, to help accelerate the little things in the game that will help him come quicker."

Washington thinks Ogando back on upswing

ARLINGTON -- Rangers manager Ron Washington thinks the worst is over for All-Star starting pitcher Alexi Ogando, who had a rough patch in the middle of the season.

"I think he had his serious hiccup," Washington said. "I don't think he's the type of pitcher that you'll see go through what he went through again where he's going to have games that will go back-to-back-to-back like that. Not to say that you wont see him have a bad inning or a bad game, it's going to happen to everybody."

In three consecutive starts against the Yankees, Braves and Mets, Ogando gave up three or more runs in five or less innings.

"He's not a dumb kid, he's a very smart kid," Washington said. "He does what he can to make adjustments, just like the league is making adjustments on him. They got to watch out, because he's making adjustments on them, too."

The 27-year-old right-hander, who is 10-4 with a 2.79 ERA, will start Friday's series opener against the Blue Jays in Toronto.

Greer on hand for Rogers' perfecto anniversary

ARLINGTON -- Rangers Hall of Fame outfielder Rusty Greer came to Rangers Ballpark on Thursday to sign autographs for the 17th anniversary of Kenny Rogers' perfect game against the California Angels.

"Time goes by quick," Greer said. "I didn't realize it had been 17 years, but they called and said it had been 17 years, and I was just like, 'Wow, it's gone by fast.' But time marches on, and some day there will be another perfect game."

Rogers will be inducted into the Rangers Hall of Fame himself on Friday, Aug. 5, but he was not in Arlington for the anniversary.

Greer made the defensive play of the game when he caught a sinking liner off the bat of Rex Hudler to lead off the ninth inning. Because Greer still lives in Texas, the catch gets brought up to him fairly often.

"Somebody once a month comes up to me and says they were at the game," Greer said. "Whenever I talk to a group, it's brought up. It's brought up quite a bit, so it had an impact on a lot of lives."

Worth noting

• The Rangers have lost nine of their last 11 against the Twins.

• Beginning with Friday's game, 16 of the Rangers' next 22 games will be on the road.

• The Rangers' 7-8-9 hitters are batting an American League-leading .275, which is 16 points better than the next place team.