John Danks described his return from left shoulder surgery last August as "starting over."

From several eyes of White Sox officials and players who watched Danks throw his first bullpen session Thursday at Camelback Ranch, they viewed a pitcher with the characteristics of one of the top left-handers in the American League.

"If you lined up 10 pitchers on the mounds out there and said 'pick out the guy who had surgery,' you couldn't have done it," Cooper said after watching Danks throw from an overhand delivery comfortably for 10 minutes. "So that is telling you something."

Danks, who had a capsular tear repaired and debris removed from his rotator cuff and biceps, wasn't surprised by his successful first bullpen session.

"At this point I'm just trying to get back to where you're completely healthy," said Danks, who started throwing off a mound in January and started throwing breaking pitches 2 ½ weeks ago. "I felt good, and the next step will be to start worrying about pitches. But right now, it's still proving to everybody that I'm 100 percent healthy."

Danks, who didn't pitch for the Sox after May 19, threw over the top with no discomfort and impressed catcher Tyler Flowers with the sharp break of the few curves he threw.

"He was letting it go," manager Robin Ventura said. "There were little things where he was trying to hold on to it a little longer and trying to generate arm speed instead of just letting it happen. Today, it looked like he was pitching as he always has."

Danks, 27, will throw his next bullpen session Sunday. His first start of the exhibition season is scheduled for March 4 against San Francisco with the hope he'll be ready by the start of the regular season.