Washington Nationals’ closer Sean Doolittle starts rehab assignment with 1-2-3 inning...

Washington got Hunter Strickland and Roenis Elías back in the bullpen before the first of three with the Miami Marlins in D.C. last night, but Nationals’ closer Sean Doolittle decided that he needed more work after throwing a sim game this past week, so he headed out for the start of a rehab assignment with the High-A Potomac Nationals.

“The sim game the other day was kind of a mixed bag,” the 32-year-old left-hander said of the 16-pitch session against his teammates in Nationals Park.

“It went well — physically I felt good, my knee and my arm felt really good,” Doolittle said, “but as far as execution, mechanically, I wasn’t where I wanted to be in order to help this team in a playoff run, so I’ll need — we’ll see how tonight goes, and then kind of go from there.”

Another positive takeaway from the simulated inning he threw, the reliever said, was that the team used Edgertronic cameras to capture his mechanics so that he and the Nationals’ staff could study more closely and identify any flaws or issues that might have led to his struggles before he ended up on the Injured List with right knee tendinitis.

“We actually put him on film,” manager Davey Martinez told reporters on Wednesday night, “... so we’re going to watch him, watch his mechanics, watch his arm angle, and just kind of see where he’s at and then like I said we’ll see how he feels tomorrow and then we’ll go from there.”

“Even though the results weren’t what I hoped they would be,” Doolittle said before he left for Frederick, Maryland, where the P-Nats were playing the Keys, “that was the first time I got video throughout this process, and we were really able to identify some things that I’ve been able to work on since then, so in a way that was really good. That’s been huge for me mentally to be able to see what I was doing and now I can better address it.”

“I need to be sharper if I’m going to help this team when I come back,” Doolittle said, as quoted by MASN’s Mark Zuckerman, in explaining the decision to keep working to get to where he wants to be before returning to the majors.

“I think the worst case scenario is: I come back, and they expect to be able to count on me and I’m not able to pitch like I need to pitch to help the team win. We’ve just got to fine tune some things. I hope it’s not too much longer.”

Doolittle gave up 13 hits, five of them home runs, and 10 earned runs total (22.50 ERA), with a brutal .520./556/1.240 line against in his last five appearances four innings pitched before the IL stint, though he had a 2.81 ERA in 49 games and 48 IP before things got ugly.

Both GM Mike Rizzo and Martinez said they expect Doolittle to return to the closer’s role when he feels ready to pitch in the majors, with Rizzo explaining earlier this month that moves at the deadline have given them more back-end options that will give the second-year skipper more options going forward.

“[Doolittle has] got the attitude and the fortitude to pitch the ninth inning,” Rizzo told 106.7 the FAN in D.C.’s Sports Junkies. “He’s shown that he can do it in the big situations, so he’s our ninth inning guy, but Davey has many, many more options to go and different routes to finish out games when Sean is down.”

In his first rehab appearance for the P-Nats, Doolittle retired three batters in order in a quick frame that probably didn’t give him the work he wanted. (MiLB.com’s box score has him with just three pitches, all strikes — but he apparently threw 13 according to subsequent reports).