Seranthony Dominguez

The Phillies have announced that pitching prospect Seranthony Dominguez is joining the active roster for the first time. To open a spot, the organization placed lefty Adam Morgan on the 10-day DL with a back strain.

Dominguez may not be a top-100 prospect in the game — or even a top-10 organizational prospect in a deep system — but he’s quite an interesting young player. The 23-year-old righty had never pitched above the High-A level entering the current season, due in part to some injuries as well as the fact that the Phils were allowing him to develop as a starter.

Entering the current campaign, though, the club decided to put the rotation work on hold, giving Dominguez a shot to show what he could do in a relief role. It’s still early, of course, but the results have been eye-popping — so much so that the youngster has now blown through both of the highest levels of the minors and onto the MLB roster in the span of about a month.

When healthy, Dominguez shows an upper-nineties heater that’s accompanied by a useful slider and a promising change-up. He has had some challenges with repeating his mechanics and staying in the zone over full starts. But in the bullpen, thus far, Dominguez has been lights-out.

Over 16 2/3 innings in 11 appearances on the year, most of those coming at Double-A, Dominguez carries a 2.08 ERA with an 18:2 K/BB ratio. He has permitted only eight hits, none of which left the yard. And Dominguez has at times generated a healthy number of groundballs, which is another aspect of his game worth watching.

It’ll certainly be interesting to see how the Phils deploy their new weapon. Given his history as a starter and multi-inning usage this year, it’s certainly possible he’ll be allowed to work multiple frames at times. Of course, the club will no doubt first look to allow him to get his feet wet.

It is not clear at this point how long Morgan will be out, but his roster spot might have been in some jeopardy were it not for the injury. The out-of-options former starter is only allowing 2.45 earned runs per nine, but that’s probably not the best measure of the quality of his work, as he has mostly been deployed against lefties and has thrown only 11 innings over 17 appearances.

Morgan is an interesting player in his own right. He has been tough to square up (.274 xwOBA vs. .275 wOBA) and has compiled 10.4 K/9. And he’s sustaining a big velo jump that he showed last year upon moving to the pen. But Morgan’s corresponding boost in swinging strikes has not carried into 2018 (he’s down to 9.6% from 16.5% last year) and he’s doling out far too many free passes (eight to this point).