(AP Photo/Pablo Martinez Monsivais)

First baseman Adam LaRoche remains on track for a rapid return from the disabled list and, with an eye on playing for the Nationals on Sunday in Pittsburgh, he said he will play in his first rehab game Thursday at Class A Potomac.

Wednesday brought LaRoche’s stiffest test yet for his strained right quadriceps muscle. LaRoche participated in a full batting practice, sprinting to first base, taking groundballs and swinging in the batting cage.

Hitting .319/.421/.504, LaRoche is eligible to come off the disabled list Sunday. He plans to play Thursday in Potomac, then move his rehab to Class AA Harrisburg on Friday night. LaRoche could make the three-hour drive to Pittsburgh in time to rest Saturday and get into the Nationals’ lineup, back at the cleanup spot, Sunday.

“We’ll see how he gets through it and make a plan there,” Manager Matt Williams said. “The first order of business is getting through today and making sure there are no setbacks, getting him to a game, see how he comes through that.”

Once LaRoche returns, the Nationals will face a roster decision. They could option Tyler Moore back to Class AAA Syracuse and keep veteran utility player Greg Dobbs, or they could keep Moore and risk losing Dobbs.

When the Nationals added Dobbs to the roster, they assumed they would jettison him once another player returned from the disabled list. Dobbs has gone 3 for 8 and played solid first base when asked. He gives the Nationals an experienced left-handed pinch hitter.

Based on Moore’s performance as a starting fill-in, the choice would be easy. Since LaRoche landed on the disabled list, Moore has gone 6 for 24 with three walks and a homer while playing excellent defense at first. But with LaRoche on the roster, Moore would be in the bench role that has not agreed with him for much of his career. As a pinch hitter, he is 7 for 55 (.127) with two homers and three walks.

“We haven’t thought about it until we have to think about,” Williams said. “We’ve got games until [LaRoche] gets back. The good thing that [Moore] gives us is the ability to left field as well. We’ll see how it goes.”

In other disabled list news, left-hander Gio Gonzalez will travel with the Nationals to Pittsburgh and play catch Friday for the first time since an MRI detected inflammation in his left shoulder. The Nationals still expect Gonzalez will miss only three or four trips through the rotation.

Bryce Harper visited a specialist in Cleveland for a check-up on his surgically repaired left thumb. The doctor told him, “everything is progressing well,” Williams said. Harper has been taking swings with his right hand only in order to keep his core muscles in shape. Soon, he’ll start working with an occupational therapist, Williams said. “It’s still really early,” Williams said.