The selection camp will conclude Tuesday before shifting to Oshawa, Ontario, for pretournament games against Switzerland on Wednesday and the Czech Republic on Friday. U.S. coach Bob Motzko would like to have his 23-player roster (three goaltenders, seven defensemen, 13 forwards) in place by the end of the first exhibition game against Switzerland.

BUFFALO -- The competition among three goaltenders vying for the role as starter for the United States at the 2017 IIHF World Junior Championship has been predictably tough to gauge during U.S. junior selection camp at HarborCenter.

USA Hockey has kept three goalies in four of the past five WJC events but kept two last year.

It remains to be seen if Motzko will have his preferred order of goaltenders established after the game against Switzerland. He may need to see one last audition against the Czech Republic two days later before finalizing his lineup.

Making the decision difficult are college freshmen Jake Oettinger (2017 draft eligible) of Boston University and Joseph Woll (Toronto Maple Leafs) of Boston College, and Tyler Parsons (Calgary Flames) of London in the Ontario Hockey League.

Parsons may have more experience in pressure-packed moments, but Oettinger and Woll offer success internationally and have had college seasons that are too good to be ignored.

"When we're hanging out, it's all fun and games and it's great catching up and hanging around with [Woll and Parsons]," Oettinger said. "But when I step on the ice I want to be the best goalie on the ice and the hardest worker. So being able to know when it's time for business and time to have fun is really important. When you're on the ice, it's all business."

Oettinger is 8-5-2 with a 1.87 goals-against average and .932 save percentage in 15 games for Boston University.

United States assistant coach Kris Mayotte, also an assistant at Providence College, has worked exclusively with the goaltenders at camp.

"You won't mistake one goalie for the other," Mayotte said. "They're all very distinctly their own goalies. They play their game and they own true to it. They've have success in winning in their careers; [Oettinger and Woll] internationally and [Parsons] with London."

Woll is 10-6-1 with a 2.51 GAA and .917 save percentage in 17 games for the Eagles. Woll and Oettinger are two of nine camp invitees who won a bronze medal playing for the U.S. at the 2016 IIHF World Under-18 Championship.

"[Woll] is the best competitor on our team at Boston College," said forward and BC teammate Colin White (Ottawa Senators). "He's always staying after practice, after workouts. He's always the last guy, one of the hardest-working kids on the team, and he's really modest about it. That's probably why he's been so successful."

At the World Under-18 Championship in Grand Forks, North Dakota, Woll had a 1.34 GAA and .947 save percentage in three games, and Oettinger had a 1.50 GAA and .934 save percentage in four games. They combined to allow a tournament-low 10 goals in seven games with a 1.57 GAA and .939 save percentage.

"The one difference between playing college hockey and playing internationally is it's a bigger stage," Woll said. "I represent Boston College but now I'll represent the United States, so there's that added pressure but I think the reward is a lot bigger."

Parsons, a second-round pick (No. 54) by the Flames in the 2016 NHL Draft, helped lead London to the Memorial Cup championship last season with a 2.15 GAA and .925 save percentage in 18 playoff games. He is 11-2-2 with a 2.46 GAA and .916 save percentage in 16 games this season.

"We're all competing for that No. 1 spot, and as a goalie that's what you want," Parsons said. "Whoever gets it, the other two will support that player. We're competing but also on the same team and the one goal in mind is to get that gold medal in the end."

Mayotte, who is making his debut on the U.S. national junior team coaching staff, broke down for NHL.com the positive attributes of each goaltender.

On Parsons: "He's not afraid to make the split save and reach for a few more pucks; he's able to make that second save but at the same time his rebound control is phenomenal. He's almost like Velcro; the puck hits him and it doesn't come back out or he puts it to the corner. If he doesn't control it, he has the athletic ability to recover."

On Woll: "He's more technical than [Parsons] but also has that athletic quickness and skating. He's very clean and very efficient, he gets to his spot and fills the net. He makes the save and moves on to the next one. He's a very efficient goalie."

On Oettinger: "The biggest of all three goalies (6-foot-4, 202 pounds). He's very good at keeping everything in front of him. You're not going to see him reach for many pucks, and he works inside his box and is good at it. With that size, he can really skate and can anticipate plays so he's usually always in the right position."