WASHINGTON — Stephen Strasburg has a strained flexor mass in his elbow and the Washington Nationals don’t know when he will pitch again, but the team said it was relieved the right-hander did not re-tear a ligament.

Manager Dusty Baker and director of athletic training Paul Lessard voiced optimism after an MRI did not reveal ligament damage. Strasburg had Tommy John surgery in August 2011.

“Normally (these injuries) come around very well with treatment and strengthening programs,” Lessard said Thursday. “It’s not a season-ending injury, but we still need to take time that he’s nice and strong because of his past.”

Strasburg left his start in the third inning Wednesday night after feeling a pinch in the back of his elbow. He walked off the field with his glove over his mouth, and immediately there was concern.

Lessard said most of the elbow appeared to be in the same condition as in May, before Strasburg signed a $175 million, seven-year contract that starts next year.

What Lessard called “a little strain” in Strasburg’s flexor mass on the side of his elbow was about the best news the team could have gotten.

“Exactly the timetable of that we don’t know, but it’s good to hear that it wasn’t what everybody was speculating that it was,” Baker said. “I did a lot of praying last night that it wouldn’t be as serious as everybody was panicking about, because how do you get worried about something that you don’t know what it is? I think it’s human nature to think the worst of all situations.”

Strasburg had just come off the disabled list Wednesday with right elbow soreness. The 28-year-old started the season 13-0 with a 2.51 ERA. He allowed 19 earned runs in 11 2/3 innings in three outings before going on the DL.

Lessard said this was a new injury and unrelated to the previous problem in the back of Strasburg’s elbow. He added this was an acute injury that could have happened on one pitch, not stress that built up on Strasburg’s elbow.

Asked about timing, Lessard said: “I’m thinking let’s take care of the swelling and get him to a pain-free range of motion, and then we’ll start a strengthening program. I’m just worried about the next four or five days right now.”

Strasburg was a National League Cy Young Award candidate before going on the DL. The Nationals have a substantial lead in the NL East and could afford to be cautious with Strasburg, but there’s no clear idea what they’d do if he can’t pitch in the playoffs.

Washington has Max Scherzer and Tanner Roark and then uncertainty, especially with righty Joe Ross, who has been out with a shoulder injury. Other than saying Strasburg’s injury won’t affect the plan with Ross, Baker is in wait-and-see mode.

“We have to do the best for the situation of what we have, and then make a determination on who is to take his place now and possibly later,” Baker said. “Or is it a better option to have Stephen, or do we not count Stephen out? Those are our options.”