Shawn Kelley is back in the Nationals bullpen after being out since April 23 with nerve irritation in his right elbow. (Jonathan Newton/The Washington Post)

SAN DIEGO — Reliever Shawn Kelley said he thought he would be activated from the disabled list Monday if all went well in his rehab assignment Sunday, but players often assign themselves more optimistic timelines than do the Washington Nationals‘ training staff. But in Kelley’s case, he was right. He threw a scoreless inning in his first and only rehab appearance for Class A Potomac on Sunday. Now he is active for Monday night’s series opener in San Diego.

“Just that I can check off all those steps, when the hitter steps in the box turn it up a notch, it still feels fine,” Kelley said. “I was able to execute, wasn’t all over the place, didn’t feel any sensations. So just to be able to notch that.”

The Nationals activated Kelley a few hours before Monday’s game and optioned outfielder Rafael Bautista to Class AAA Syracuse to make room. In so doing, the Nationals shorten their bench from the usual five to a difference-making four. They also increase their bullpen from the usual seven to eight, a much-needed boost in depth for a group that has been overworked from top to bottom.

Kelley last pitched April 23 in San Francisco, where he surrendered a home run then bounced a pitch that seemed to indicate trouble. Kelley ended up with a diagnosis of nerve irritation in his elbow, a problem he has experienced before. After two Tommy John surgeries and years of heavy slider use, his elbow is prone to trouble.

“It’s nerve-racking every time because of my history, but it’s been 12 days, 13 days or something?,” Kelley said. “To be back active, it’s a good thing. Now it’s just avoid that and help us keep winning.”

Because of that, the addition of Kelley alone doesn’t exactly give the Nationals innings and innings of relief depth. That he pitched Sunday means the Nationals would probably prefer to stay away from him Monday, though he only threw six pitches in that outing, and he and his manager both say he is available. Still, the more times he throws on consecutive days, the more he risks flare-ups in that elbow.

“When it happens, it’s always scary because it reminds me of the couple times I’ve had Tommy John and I felt that, too,” Kelley said. “But since then, the couple times it’s happened, the tingling and the numbness — I’ve just kind of accepted that it’ll go away. That it’s not the end of my career.”

Kelley has struggled at times this season, sometimes looking rejuvenated after his nightmare 2017 season, sometimes looking more like the 2017 pitcher than anything else. He owns a 4.50 ERA in eight appearances, and has allowed three home runs in six innings. Home runs were a problem for Kelley in 2017, and seemed linked to the state of his elbow, which gave him trouble last year, too. Health will always be a concern, but for now, the veteran is around to help a bullpen that cannot seem to catch its breath — as long as he doesn’t lose feeling again.

“Maybe I’ll up the meds and stop feeling the tingling,” joked Kelley, who can’t do much but laugh at the finicky right elbow that earned him his spot in this bullpen, but keeps threatening to take it away.

Read more on the Nationals:

The growing legend of Juan Soto

Is Ryan Zimmerman’s injury worse than it seems?

Nationals are wise to be playing it safe with their stars

Nationals at Padres series preview: Another trip to the West Coast