McDonald falters but will remain in rotation as Houser shifts to bullpen role

MIAMI -- The Giants have settled their immediate pitching plans.

With Tyler Mahle expected to return from the injured list and start Wednesday against the A's, manager Tony Vitello said before Saturday's 6-3 loss to the Marlins at loanDepot park that Trevor McDonald will remain in the rotation, with Adrian Houser shifting to a bullpen role.

The move allows McDonald -- who gave up five runs (three earned) on three hits, hit three and walked three batters, while striking out just one Marlin -- to keep his spot in the rotation.

To Vitello, Houser has found a rhythm in the middle innings, running into the most trouble when facing a lineup for the first and third time in a game. Now midway through the season, the switch in roles aims to give the right-hander a chance to settle down.

“He wants the same thing as everybody else, just wants to do better,” Vitello said. “He’s really found a rhythm in the middle of outings. Those are things he's done well before in the past. So, I think just getting to that rhythm that he's found when he starts to navigate through a lineup.

“It's been a little frustrating for him from the start ... but he's good, he's ready to rock and roll.”

In 14 starts this season, Houser sports a 9.64 ERA in the first inning. Opposing hitters are batting .418 with a 1.148 OPS against Houser when they face the right-hander for the third time. Left-handed hitters are also batting .339 against Houser with nine home runs in 168 at-bats.

Houser was the Giants' biggest free-agent addition over the offseason, signing a two-year, $22 million contract to be a starter. The 33-year-old owns a 5.73 ERA and a 1.58 WHIP.

Houser lasted one inning and threw 29 pitches in his most recent outing against Atlanta on Tuesday. He has reached the sixth inning in just six of his 14 starts.

The one thing that has shown up consistently when Houser has done well in innings is getting behind his offspeed pitches, something that has faltered throughout the season.

“I think just throwing those offspeed pitches with conviction,” Vitello said. “There's been times where he's kind of leaked out with his body and he's underneath those pitches. And I'm not in the box, but there's times where, from the dugout, it's telegraphed.”

As for whether the move is permanent, Vitello said the Giants will continue to take things series by series. With the Miami series mapped out and Logan Webb scheduled to close it out on Sunday, the off-day Monday will serve as a chance to regroup.

“We'll see how things go with Mahle [in his next start], because it's also going to be a pitch-count situation, just coming back and building up that deal,” Vitello said. “Most likely with [Houser] in the bullpen, and looking at the [opposing] lineup and deciding if there's a specific role to give him, or just have a great arm out of the bullpen.

“Something may click for him or somebody else, and then something may open up for another reason. But all you got to do is look to the past. He's capable of giving you a quality start.”

The 10-year veteran owns a 4.20 ERA in his career.

For now, the Giants should be slated to start Robbie Ray on Tuesday and Landen Roupp on Thursday. They will also need to make a corresponding roster move when Mahle is activated.

McDonald, meanwhile, will get his chance to stick in the rotation going forward.

Vitello said the right-hander's mentality is exactly what the Giants want because “his stuff is there.”

“For him, I think again, just a little bit out of sorts with the delivery [today], and the guy's as competitive,” Vitello said. “He's similar in so many ways to [Landen] Roupp and [Logan Webb], but I think it’s going good for him and, for whatever reason, got derailed a little bit. But he's always a diligent worker and always very competitive.”