PEORIA, Ariz. -- Padres third baseman Chase Headley's MRI on his strained right calf on Monday confirmed the original diagnosis.

San Diego manager Bud Black said Tuesday that Headley has a Grade 1 strain of the gastrocnemius muscle, which is one of three muscles in the calf.

The Padres haven't announced a specific timetable for Headley's return, but it will largely be a function of how the calf is feeling and how it responds to rest and rehabilitation.

At this point, both Black and Headley seem to think Headley will be out of action for two to three weeks during Spring Training. That will still leave the 29-year-old time to get caught up, offensively and defensively, before the Opening Night game on March 30 against the Dodgers at Petco Park.

"The last day and a half has been a lot better than the first day and a half," Headley said. "I'm able to walk around pretty much normal now, which is a good sign. But it's feeling better than it did a couple of days ago. It's definitely improved a ton.

"My guess is pretty much the same when we discussed a timetable."

Black has mentioned previously that Ryan Jackson, Alberto Gonzalez, Alexi Amarista and Minor Leaguer Jace Peterson will see time at third base in Cactus League play in the interim.