Mark Teixeira took grounders, took some swings and did light jogging before Saturday's Yankees-A's game, but the first baseman hesitated to say specifically when he could return to the field.

Teixeira, out since aggravating a calf injury Sept. 8, will travel to Tampa on Sunday to take part in individual workouts at the Yankees' complex.

He may also play in instructional league games.

Teixeira said his injury is progressing, but he's still concerned about pushing off on his calf or trying any explosive movements.

"Grounders aren't going to be a problem, hitting's not going to be a problem," Teixeira explained. "It's when you have to accelerate, hit that first step, or maybe a jog to a run. If I overload it ... it feels a little tight, a little sore."

That's why Teixeira refuses to put a timetable on his return. Yankees GM Brian Cashman has mentioned the possibility of Teixeira returning near end of next week, when the Yankees are in Toronto.

Teixeira, however, hesitated to speculate.

"I'm just going to take it day by day; that's the plan this time around," he said.

When Teixeira originally injured the calf Aug. 27, he said he and the training staff tried to get him back on the field as soon as possible. He was limited in the field when he first returned earlier this month. Teixeira aggravated the injury Sept. 8 when he dove to try and beat a game-ending double play at first.

So he's being cautious this time around. He won't return if he can't explode out of the batter's box or dive in the field.

"I want be comfortable that I can do those things and not blow out again, because then we're right back to square one," said Teixeira, who is hitting .255 with 23 homers and 81 RBIs.

"The first game of the playoffs, we're down one run and I need to beat out a double or beat out an infield hit and I blow out and miss the rest of the playoffs, then we accomplished nothing."

Teixiera said the calf is feeling better but he still feels tightness when he's walking up stairs or tries to "explode" using his calf. The next step for Teixeira is to increase the intensity of his running.

PEN PLANS: Joe Girardi said both David Robertson and Rafael Soriano may not be available for Saturday's game. Robertson has pitched in three consecutive games. Soriano had two saves in the Yankees' doubleheader sweep of Toronto on Wednesday and then blew a 1-0 lead in the ninth on Friday night.

Girardi said Soriano is feeling fine and that there is no lingering physical issue with the Yankees' closer, who has been phenomenal since taking over the injured Mariano Rivera.

NO GARDY: Girardi said earlier this week that Brett Gardner may be activated soon. But that hasn't happened yet. And Girardi has declined to provide any information on it, other than to say there's nothing physically wrong with the speedster.