(Julio Cortez/AP)

This challenge was unexpected. In Friday’s live batting practice session, it bugged him that hitters Chad Tracy and Jhonathan Solano were hitting him hard. Only later did Storen discover that bullpen catcher Nilson Robledo was telling the hitters which pitches to expect.

“They didn’t tell me until afterward,” Storen said. “I was thinking: ‘Man, they’re seeing it pretty well.’”

Pranks aside, Storen threw 40 pitches in Friday’s session, going “full tilt. He reported feeling fine — and on track for a return in less than two weeks. On Monday, he is scheduled to throw about two to three innings of a simulated game, the likely final step before beginning minor league rehab assignments. Storen is targeting a return to the Nationals for the first game following the July all-star break.

“I’m pretty amazed,” Storen said. “My elbow feels better now than I think it did ever last year. Even last year, after you’re down it would be a little swollen. I just thought that was normal. Now it feels really good.”

Forced by the surgery to rebuild his arm strength, Storen said he has developed a better feel than ever for his pitches and can throw a sinker and change-up without a problem.

“That was the thing that got me when I tried to come back before I had the surgery: Anytime I tried to sink it or throw a change-up, I couldn’t get out there,” he said. “Now that I can, it’s pretty exciting. And that’s the mind-set I had once I had the surgery: I want to come back better. Because I have the time to do it, and I have the peace of mind, too. That’s probably the biggest benefit of getting it done. If you had told me I was going to miss half the season, that’s brutal. But a positive mind-set, that’s definitely the way I look at it.”

As for his return, Storen said the end is in sight.

“This last 10 percent of the rehab is just as important as the beginning,” he said. “It’s kind of like doing a big school project. You’ve just got to do the annoying little things. You’ve got to do the bibliography. You really don’t want to do it, but you’re going to get counted off if you don’t.”

Tracy is also on the same timetable to return immediately following the all-star break as he recovers from surgery to repair a torn muscle in the right side of his groin, Manager Davey Johnson said. Johnson said Tracy could soon serve as a designated hitter in a minor league rehab assignment and perhaps play in the field in a minor league game or two by early next week.

“Mostly I’m concerned can he hit and is it okay to just run the bases,” Johnson said. “I think he thinks he could do that right now.”

The left-handed batter was a vital pinch-hitter for the Nationals — going 6 for 18 and with nine RBI off the bench — and a late-game presence Johnson covets.

“I really love his bat,” he said. “He won a bunch of games for us with his bat prior to leaving. His injury was just as severe a loss to the team as a Michael Morse or a Jayson Werth or a [Wilson] Ramos. Because he really had a big role on this ballclub, late-inning pinch hitter, trying to win a tie game against their best pitcher. He was winning those battles. As far as my thinking, he was as big or bigger than any of the regulars we lost because he was always going to be there in crunch time.”