BOSTON—The goaltenders pitted against each other on Tuesday night in Boston weren’t in opposite nets. The Capitals’ second preseason game featured a lineup that Coach Barry Trotz referred to as a “worker group,” more grinder than skilled. But within that collection of players, most of whom are unlikely to make the NHL roster, were the two goalies vying for Washington’s backup role.

Justin Peters played the first period and a half and Philip Grubauer played half of the second period and the third, plus the 12-second overtime, giving the coaching staff an opportunity to see both against the same Bruins competition. One of the two is expected to backup Braden Holtby this season.

Both had 15 saves, though Grubauer allowed Boston’s two goals, one on an odd-man rush 12 seconds into the three-on-three overtime. Each faced two penalty kills, giving Trotz and goaltending coach Mitch Korn an even look.

“I thought they were really good,” Trotz said after the 2-1 loss. “I think the one goal that went on Grubauer sort of rolled up on him. Probably would like that one back, but they made a couple of good saves to make up for that one, and Petey was really solid. I thought Grubauer probably had some of the, a couple more harder chances than Petey, but Petey was really, really good.”

Peters appeared in just 12 games for Washington in 2014-15 despite remaining mostly healthy. He had two encouraging outings, a shootout loss in relief against San Jose and a shootout win over Florida, but then allowed at least three goals in each of his next eight outings and only made two starts after Jan. 1.

Peters finished with a 3.25 goals against average and a .881 save percentage. He was passed over during the first round of the playoffs for Grubauer, who had spent the season in Hershey, when Holtby got sick and the Capitals needed an emergency replacement for Game 2.

He had a left knee operation in August, and he said he didn’t feel any discomfort on his knee after Tuesday night’s game.

“It was a lot of fun,” Peters said. “It was fun to get into a game situation, it’s been awhile so it was a lot of fun to get out there and get the competitive juices flowing. I felt pretty healthy and that was the most important thing.  It was just fun to get out there.”

Both Peters and Grubauer are eligible for waivers, but with Grubauer six years younger, he would be a greater risk for getting nabbed upon reassignment. Both are also on one-way contracts, though Peters’ deal carries a hit of $950,000, and Grubauer $750,000, but both would be exempt from counting against Washington’s salary cap while in the minors.

Grubauer said the David Pastrnak goal he allowed in the third period was a result of him not sealing up the post, the puck squeaking through between his pad and the pipe. As the competition for the backup goaltender spot continues throughout training camp, this is likely not the last time he and Peters will share the ice, and Grubauer’s mindset is simple.

“Don’t make any mistakes,” he said.