While Stephen Strasburg was placed on the disabled list and shut down temporarily because of elbow soreness Monday, fellow Nationals starter Joe Ross is making progress in his long recovery from shoulder inflammation.

Ross threw a bullpen Tuesday afternoon at Camden Yards, his first time throwing off a mound since his initial rehab assignment was terminated after two minor league outings on Aug. 5, pushing back his return to an unknown date. The 23-year-old right-hander threw “25, 30 pitches.” He reportedly is feeling stronger now than the first time he tried coming back from his stint on the disabled list, which began on July 3.

Ross explained the only change in his rehabilitation regimen has been an increase in rest time. Other than that, he’s taking the same steps he did in his initial comeback try.

“I just feel the extra time gave me a little bit of a kick-start the second time around,” Ross said.

If he continues progressing, the ideal plan would be for Ross to throw in a simulated game and make a few rehab starts, increasing his pitch count with each outing to build stamina and remove the rust that accumulates from not pitching in a major league game for a couple months. That was the plan hatched last month in his initial attempt at returning.

Schedule constraints, however, may force the Nationals to use a different procedure. With the minor league season coming to a close, Ross might not have the opportunity to pitch for affiliates on a rehab assignment before joining the Nationals’ rotation. One possible solution? Putting him in the major league bullpen.

“One of the things I was talking to Joe about, ‘Hey man, you might have to come back in a reliever role,’ ” Nationals Manager Dusty Baker said Monday. “He’s gonna have a problem getting rehab time because the season ends in [13 days].”

The assumption is Ross would eventually join the starting rotation before the end of the season after a few relief appearances. But Baker’s idea of potentially transitioning Ross to the bullpen seems to be a feasible solution. Barring a Strasburg setback, the Nationals know their top three for their four-man postseason rotation and it’s a formidable trio: Strasburg, Max Scherzer and Tanner Roark (maybe in that order, maybe not). The fourth slot is the question mark.

The Nationals don’t necessarily need Ross, who has a 3.49 ERA in 95 1/3 innings, in the rotation at the moment because they have a surplus of starters and an eight-game lead in the National League East. Reynaldo Lopez, Lucas Giolito and even A.J. Cole, who pitched seven innings against the Orioles on Monday, have all filled in when needed. Veteran Mat Latos and Austin Voth are also options in Class AAA Syracuse. The Nationals have the luxury of not needing to rush back starting pitchers or having them perform through pain — it’s why, they say, Strasburg was put on the disabled list Monday.

The answer regarding the No. 4 starter right now is probably Gio Gonzalez, who has pitched better following a midseason swoon and is the Nationals’ only left-handed option. But there are other choices, including Ross — if he is stretched out and healthy — and Lopez.

“We haven’t talked about it,” Baker said Tuesday. “Just common sense will tell you how much time is left to get ready and we are in the middle of a pennant race. I haven’t talked to Mike [Rizzo] or anything. I just talked to Joe about it. So I just didn’t want him surprised that that was the case. We want him, if possible, if he’s ready, on the playoff roster. That’s always a possibility with your fourth or fifth starters to be in the bullpen anyway. So we’ll see. We’ll see how his progress comes along.”

Ross has pitched out of the bullpen three times in his major league career, all in his final appearances last season because the Nationals wanted to manage his innings. He threw three innings and didn’t allow a run. It was a tiny sample size, but, as expected with shorter doses, he threw the ball harder than he had as a starter — his fastball climbed to 94.4 mph and his slider to 85 mph.

That all would all be moot if Ross finishes the season as a starter, which he said Tuesday is his objective. But the Nationals have options and one is having the hard-throwing righty bolstering the bullpen in October.