ST. PETERSBURG -- Jason Bartlett said he felt "close to 100 percent" after a workout on Monday and the shortstop could be activated from the 15-day disabled list as soon as Thursday's game in Kansas City.

Bartlett has been sidelined since July 3 with a right knee sprain, an injury suffered when stealing third base in a win over the Red Sox on June 2.

On Monday, Bartlett ran the bases for the first time since the injury -- in addition to taking ground balls at short -- and afterwards said his knee responded "a lot better" than expected.

"I'll be ready to go come Thursday," Bartlett said.

Rays manager Joe Maddon was vague on Bartlett's exact return date -- saying it was likely to come during the seven-game road trip that starts Thursday -- but he did mirror the shortstop's enthusiasm after Monday's workout.

"Watching him run, there was no hesitation," Maddon said. "I'd say he didn't run 100 percent, I'd say maybe 75-80 percent it looked like. And without any kind of difference in regard to what he looked like normally."

Bartlett is scheduled to be evaluated on Tuesday -- with some soreness expected -- and then evaluated further on Wednesday before an exact course of action is decided.

A cornerstone in the Rays revamped infield defense, Bartlett said he is still struggling with running to the left side, and has been wearing a brace on his knee to help alleviate some pressure.

In his absence, the team originally recalled Reid Brignac and Ben Zobrist from Triple-A Durham, but optioned Brignac back to Triple-A on Tuesday to clear a roster spot for right-hander Al Reyes.

While the obvious move would be for the Rays to option Zobrist when Bartlett is deemed ready, Maddon was unsure about throwing Bartlett back into the everyday grind "right out of the shoot".

If Zobrist does get optioned back to Durham, Evan Longoria will serve as the team's emergency shortstop, but if the Rays elect to keep Zobrist as insurance, a corresponding roster move could get dicey.

Acquired in an offseason trade with Minnesota, Bartlett started 77 of the Rays first 84 games this season before landing on the DL. The 28-year-old shortstop has combined with second baseman Akinori Iwamura to help form a deadly double-play combo, and his return would help stabilize the Rays middle infield.

Prior to his injury, Bartlett was hitting .256 with 24 runs scored and 18 steals.