[Updated 2:53 p.m.]
Stephen Strasburg threw a bullpen session on Saturday afternoon and afterwards took his clubhouse media session as an opportunity to clear the air on what has been ailing him in recent days.
Contrary to some reports, Strasburg does not have a problem with his shoulder. It is instead his ankle, which caused him to overcompensate on his pitching mechanics and as a result his back tightened up. He hurt his left ankle late in spring training and was briefly sidelined before the Nats' opened their regular season schedule.
Strasburg felt fine after throwing on Saturday and believes he can return to the Nationals rotation early next week if all goes well on Sunday.
"I felt good. No problems. I actually threw for the first time without having my ankle taped up. It was more of a mental thing. I felt good, my ankle didn't feel bad and that helped my alignment be better," he said.
Strasburg plans to play catch on Sunday to test his ankle and back once again, but he thinks the back tightness has been alleviated after seeing a chiropractor.
"It was just night and day. I was happy with it. I thought that's what was going to happen and that's was what happened," he said of the appointment.
With his back tightness now cleared up, Strasburg wanted to set the record straight about his injury, that it had nothing to do with his shoulder.
"It's what caused my back tightness. It was never a shoulder issue. What caused my back tightness was I think an extension of a change in mechanics from my ankle. I just started throwing across my body a little more than I have done in the past," he said.
Strasburg has been working on his mechanics with pitching coach Steve McCatty, who initially noticed Strasburg was favoring his ankle while watching film of his recent outings.
"We were looking at a lot of video and he started to notice that. I was landing a little bit more too much from where I need to be. He kind of diagnosed that," he explained.
"It was something where I felt like I could pitch. My arm felt good, my velocity felt good. Then it got to the point where there was a little irritation in my back and I realized it. It was like a light bulb went on. It is such a small adjustment. It's something that you can't really see unless you slow it down and know what you're looking for. I knew what I was feeling. I didn't know what it was."
Strasburg was removed from his previous start on May 5 against the Marlins. He is 2-3 with a 4.73 ERA in six outings this season.