Seranthony Dominguez, who moved last month to triple A after just 13 innings in double A, continued his rapid ascent on Monday. The Phillies promoted the hard-throwing reliever to the major leagues after just three games at triple A.

Dominguez, armed with a 98-mph fastball and wipeout slider, has the profile to be a closer. But manager Gabe Kapler said the 23-year-old righthander was not pushed to the majors because of Hector Neris' blown save on Sunday in Washington.

A roster spot opened when Adam Morgan was placed on the disabled list with a back strain. Dominguez retired 11 of the 12 batters he faced in triple A. An early-May promotion seemed unlikely when the Phillies decided this winter to transition Dominguez to the bullpen. But he racked up 21 strikeouts in his first 16 2/3 innings of relief. He seems ready.

"There's a lot of reasons to like Seranthony," said Kapler, who trekked last month to Reading and watched Dominguez pitch. "The first reason is he's got a really big fastball, and the slider and change-up play well also. But the thing that I find most impressive about him is his composure and his maturity and his mental readiness.  Those are the things that stood out in spring training and continue to stand out as we watch video, as we look at numbers as we remember back at spring training."

Kapler said throughout the offseason that he did not want to assign roles to his relievers, but it has been obvious in the first five weeks of the season that Neris assumed the closer role. The manager's idea of a roleless bullpen may have been challenged as he looked to a bullpen comprising relievers who were used to having roles.

Neris succeeded last season pitching primarily in the ninth inning. Perhaps it would have been foolish to then push him this season into a hybrid role in which he's pitching the seventh one night and the ninth the next, depending on where the key outs are.

Dominguez was a starting pitcher for his first six professional seasons. He has entered games this season in four different innings. He does not have a role, and perhaps he could be the perfect pitcher to be Kapler's "closer," where he is not tied to the ninth inning, but instead tackles the highest-leverage situation wherever that may be.

"He's the type of guy that can take down meaningful innings for us," Kapler said. "I believe that one way to manage a bullpen is to look for pockets in the game that are high leverage and use our guys to get big outs in that situation. We're always looking to put our relievers and our pitchers in the best possible position to succeed as well as giving the Phillies the best chance to win every night. I think I've had this conversation with all of our relievers and I'll continue to have it: There is no one specific role relievers are going to be used in."

Extra bases

Jerad Eickhoff, on the disabled list with a back-muscle injury, is expected to pitch Tuesday in an extended spring training game in Clearwater, Fla. … Pat Neshek (shoulder) played catch Monday and is progressing very well, Kapler said. Neshek said last week that he expected to join the team next week in St. Louis.  … Mark Leiter Jr. (flexor strain) pitched Sunday in a rehab game and "pitched great," Kapler said. … Aaron Nola will start Tuesday night against Giants lefthander Derek Holland.