Storen will play catch for the next couple days before going back on the mound, Manager Davey Johnson said. While Storen’s progress has encouraged all parties, his throwing schedule still makes mid-April an optimistic estimate for his regular season debut.

Storen’s elbow inflammation has opened up a competition at the other end of the bullpen between Ryan Mattheus, a rookie last season, and veteran Chad Durbin, who signed a minor league contract this winter.

The first thing to know about the competition is this: Mattheus has a remaining minor league option, and Durbin’s contract includes an opt-out clause that allows him to seek another team if the Nationals do not put him on their 25-man roster. Both have pitched well this spring, but the Nationals could ensure that they keep both players in the organization by optioning Mattheus and taking Durbin north.

“All that’s taken into consideration,” Johnson said.

Johnson noted that Durbin could both set up and pitch in long relief, while Mattheus is more of a set-up reliever only.

Durbin has been excellent this spring, allowing three earned runs in 14 1/3 innings while striking out 13. Two of those earned runs scored when he came in to relieve Chien-Ming Wang, who had injured a hamstring, the kind of unexpected appearance that is rare in spring training. Durbin has allowed one base runner in his last three appearances, a span of five innings. In six of his nine appearances, Durbin has thrown multiple innings.

Durbin has been away from the team for the past three days, tending to his wife Crystal in Louisiana after she delivered the couple’s second baby boy. He will rejoin the team tomorrow in Fort Myers.

Mattheus played a significant role after he joined the Nationals last year, posting a 2.81 ERA in 32 innings out of the bullpen. This spring, Mattheus has allowed five earned runs in 12 innings while striking out nine. Both Johnson and Mattheus’s teammates have frequently praised his stuff.

“A lot depends on not so much what they accomplish here to the end of spring,” Johnson said. “They’re not auditioning for me, like they probably think they are...It’s how they come through these next three days and what’s going to be best for right now with an eye on tomorrow.”