"The whole process has been very smooth. No hiccups. I felt really good the whole time. Almost too good," Rosenthal said Monday during a conference call with reporters. "Especially there, after the All-Star break, I was kind of anxious, thinking I might be able to pitch before the season was over. But the plan all along from my doctor was just to take this year off, so we stuck with that plan."
Rosenthal, the former St. Louis Cardinals closer, agreed last week to a deal with the Nationals, who officially announced Saturday that they signed him.
He joins holdover lefty closer Sean Doolittle at the back of Washington's bullpen.
Rosenthal said he hasn't "really had too many conversations" yet with the Nationals about how they plan to use him.
"Obviously, I mean, I think the plan is just being in high-leverage situations and hopefully, as a team, we're winning a lot of games and have a lot of those opportunities to go around," he said. "But for me, it's not something where I need to know exactly what my role is going to be."
Rosenthal also said he doesn't think there will be any sort of "hard stop or exact limitations to what I'm going to do," in terms of number of innings or appearances as he returns from reconstructive elbow surgery.
In Washington, he'll be reunited with Nationals pitching coach Derek Lilliquist, who used to hold that position with the Cardinals.
The Nationals gave Rosenthal a 2019 contract that guarantees him $7 million and gives the righty a chance to earn an additional $8 million in performance bonuses. The agreement includes a $15 million conditional player option for 2020 that kicks in if Rosenthal appears in 50 games next year or has 30 games finished.
The 28-year-old Rosenthal is a hard thrower with 121 career saves, all for the Cardinals, including a career-high 48 in 2015, when he was an NL All-Star. He had 45 saves in 2014.
He had only 14 saves in 2016, and 11 in 2017 before getting injured. Rosenthal was released by the Cardinals in November 2017, a few months after his operation.
"By the time I started throwing, I was really chomping at the bit to get back into it. And I had done so much exercises and rehabilitation work that my arm probably felt the best it's felt in the past five or six years," Rosenthal said. "So I was excited to try it out -- and also kind of let down when I did do my first throwing session and I realized that I was only allowed to throw it a maximum of 40 feet and for only so many throws. I was like, 'Really? That was it?' I'm used to throwing really hard for an extended amount of time, every single day."