MLB Game Preview - Seattle at Washington

Wed May 24, 2017 7:05 PM EDT

WASHINGTON -- One of the few Washington Nationals not performing at his 2016 level is right-handed pitcher Tanner Roark, who is slated to start on Wednesday against the Seattle Mariners.

Roark is 3-2 with a 4.73 ERA through nine starts, and he has allowed 48 hits, including six homers, in 51 1/3 innings. Last year, he had a 2.83 ERA in 34 games, including 33 starts, while earning 16 wins.

Washington catcher Jose Lobaton still has confidence in Roark.

"He's a battling guy. He always tries to do his best," Lobaton said Tuesday. "He has four or five pitches. He is a guy that you want to be behind the plate and catching."

Roark gave up 11 hits and six runs in 6 1/3 innings in a loss in Seattle during the 2014 season in his only showing against the Mariners. That was his first year as a regular in the rotation, and he won 15 games.

While Roark makes the 91st start of his career, Seattle rookie Sam Gaviglio (0-0, 1.29) will make his second career start and his third overall appearance Wednesday.

The Oregon native debuted out of the bullpen at Toronto on May 11. He then started Thursday against the Chicago White Sox and allowed three hits and no runs in five innings during a no-decision.

Gaviglio will face a Washington lineup that has a major-league-best .277 average. The Nationals have three of the top nine hitters in the National League: Ryan Zimmerman (.372), Bryce Harper (.346) and Daniel Murphy (.325).

The Seattle pitcher will have a tough challenge as the Nationals collected 15 hits in a 10-1 win over the Mariners Tuesday, belting four homers. Anthony Rendon had two homers and a double while driving in five.

"You can't give in to them. You have to make your pitches and trust your stuff," Gaviglio said on Tuesday, a day after he turned 27.

The Mariners got a boost Tuesday as second baseman Robinson Cano came off the 10-day disabled list, though he went 0-for-3. One day earlier, catcher Mike Zunino was called back from Triple-A Tacoma, where he was working on his approach at the plate.

"It is great to have those guys back. We are not completely healthy yet, but we are moving in the right direction," Seattle manager Scott Servais said.

Zunino is following a detailed pregame routine, and Servais said Tuesday there were about seven bullet points he spoke to the catcher with upon his return from Tacoma. It must have worked, since Zunino hit a solo homer Tuesday for the only Seattle run.

"Hopefully I can turn it around here. I was hitting the breaking ball better down there," said Zunino, who batted .293 (12-for-41) at Tacoma from May 5-21.

The Nationals hope leadoff hitter Trea Turner can warm up. The shortstop hit .342 in 73 games last year but is batting .241 this season.

"The league has adjusted to him. Now it is up to him to adjust," Nationals manager Dusty Baker said.