"I really have no reservations, if Danny needs a day here coming up, we're going to fire Gamel in there," Servais said. "And I'd prefer it be on a day we had more of a fly-ball pitcher on the mound."
Gamel has taken grounders and worked at first base before games since early June, something the Mariners planned to do to provide more opportunities for him to get in the lineup, Servais said.
But he hasn't been a serious option to start there until now. He got a small sample of in-game action at first, playing the eighth inning in the Mariners' 10-4 loss to Rangers on June 16.
Gamel said he's comfortable playing first base if the situation called for it.
"I know it's different than games, but I'm comfortable taking grounders over at [first] and seeing throws," he said. "You get a lot of early work over there, so I'm definitely feeling more comfortable over there.
"I'm willing to do whatever to keep me in the lineup."
Danny Espinosa, who Seattle signed on Monday to be its utility infielder, also has limited experience playing first base.
• Center fielder Jarrod Dyson sat out his second straight game Monday night against the Red Sox with a hyperextended big toe on his left foot from slamming into the wall on Saturday. Servais said he was feeling better Monday, but still isn't 100 percent and "hopefully will be closer to ready to go tomorrow."
With the Red Sox starting three consecutive left-handers, Dyson likely won't be needed to start until the weekend series against the Mets, but Servais would like to have him available as a pinch-runner or backup if possible.
• Hisashi Iwakuma has continued playing catch nearly every day in pregame work, but there still is no timetable for when he'll throw a bullpen session. The veteran right-hander hasn't pitched in a game since May 3 and was moved to the 60-day DL on Monday to open a 40-man roster spot for Espinosa.
"He's pain-free and no issues there," Servais said. "He's getting stretched out a little. He's out to 140 feet throwing, which is good. Once you get to the long-toss point and are getting on it pretty good, the next step is to get on the mound. But I haven't heard a date yet for him getting on the mound."
• Marco Gonzales, the 25-year-old left-hander acquired from the Cardinals last week, made his first start for Triple-A Tacoma on Monday and allowed three runs on six hits over six innings, with one walk and five strikeouts in a 4-3 victory over Sacramento at Cheney Stadium.
Josh Horton is a reporter for MLB.com based in Seattle.