The Washington Capitals started the process when they signed University of Alaska-Anchorage forward Mason Mitchell to a two-year, entry-level contract Thursday.
NHL.com takes a look at some of the top college free agents (in alphabetical order) who could be the next to sign with an NHL team:
Zach Aston-Reese, C, Northeastern
Aston-Reese, a 22-year-old senior, is the top scorer in the NCAA with 30 goals in 36 games, and he's tied for first with 62 points. He's tied for third with 13 power-play goals and tied for first with four shorthanded goals.
"He's got size (6-foot, 204 pounds), he's got tenacity, he can score," said Dave Starman, a college hockey analyst for CBS Sports Network and ESPN. "He makes his linemates better and he has been good in big games. I think his game would translate to the NHL. He's a classic late bloomer."
Northeastern will play at Boston University in a best-of-3 Hockey East Tournament quarterfinal series March 10-12.
Daniel Brickley, D, Minnesota State
Brickley (6-3, 205) is a 21-year-old sophomore with a left-handed shot. He's eighth among NCAA defensemen with 30 points (eight goals, 22 assists) in 28 games. Half his offensive production (four goals, 11 assists) has come on the power play.
"He's a good short-area skater," Starman said. "He's a good passer. And he's got a really good defensive stick. Good in his own end, stays within his limits, smart."
Minnesota State will play at Michigan Tech in the best-of-3 Western Collegiate Hockey Association semifinals March 10-12.
Austin Cangelosi, C, Boston College
The senior leads Boston College with 17 goals and is second with 30 points in 35 games. Cangelosi, 22, also leads the NCAA with a 64.9 percent success rate on faceoffs.
"He's undersized (5-7, 173), but really skilled and he can score," an NHL scout said.
Boston College will host Vermont in a best-of-3 Hockey East Tournament quarterfinal series March 10-12.
Sheldon Dries, C, Western Michigan
Dries, a 22-year-old senior, has been the captain at Western Michigan the past two seasons. He's second on the Broncos with 15 goals and 29 points in 34 games.
The leadership and production could make him a desirable prospect for NHL teams despite his 5-9, 185-pound frame.
"GMs love captains," the NHL scout said. "He can score, he's a penalty killer. He centers two really high-end players, [Griffen] Molino and [Matt] Iacopelli (Chicago Blackhawks) and made them both better players. And he blocks a ton of shots."
Western Michigan will host Nebraska-Omaha in a best-of-3 National Collegiate Hockey Conference Tournament quarterfinal series March 10-12.
Spencer Foo, RW, Union
The junior forward, 23, is tied for fourth in the NCAA with 56 points in 34 games, and he's seventh with 22 goals. His plus-28 rating leads all players.
"He's greasy," Starman said. "He just does a lot of little things that are fun to watch. He's got electric speed, hands, guts. He's not afraid to try something difficult. He's been good. He's just fun to watch and he plays with an edge."
Foo (6-0, 180) could remain at Union for one more season. His younger brother, Parker, will be a freshman there in 2017-18.
Union will host Princeton in a best-of-3 East Coast Athletic Conference Tournament quarterfinal series March 10-12.
Parker Gahagen, G, Army
A change in United States Department of Defense policy will allow Gahagen, a 23-year-old senior, to delay his military service to pursue a hockey career.
In 31 games, Gahagen (6-2, 193) is 16-11-4 but has a 1.90 goals-against average and .936 save percentage that rank in the top five in the NCAA. His five shutouts are tied for second.
"One of the reasons Parker's had a great season is because the time that he puts in," Army coach Brian Riley told CollegeHockeyNews.com. " … I think it's a combination of a lot of things, but certainly Parker's work ethic [has] put him in a position to be as successful as he is."
Army will host Mercyhurst in a best-of-3 Atlantic Hockey Tournament quarterfinal series March 10-12.
Alexander Iafallo, C, Minnesota-Duluth
A 23-year-old senior, Iafallo (6-0, 185) leads UMD with 37 points (15 goals, 22 assists) in 34 games.
"He is another guy that has just gotten better with age," Starman said. "He's got really good speed, can score in many different ways. He's a really good net-front presence. And the most underrated part of his game is how good he is defensively."
UMD hosts Miami in a best-of-3 NCHC tournament quarterfinal March 10-12.
Justin Kloos, C, Minnesota
A 23-year-old senior, Kloos (5-9, 179) is in his second season as captain. This season he has 41 points (17 goals, 24 assists) in 34 games and his six game-winning goals are tied for the most in the NCAA.
Minnesota's home, Mariucci Arena, has an international-size rink, but Starman said that shouldn't preclude Kloos from reaching the NHL.
"He's got a lot of skill, got a lot of speed," he said. "On the big ice he's been able to take advantage of it to find more room for himself. But I think beneath the dots he's dangerous. He's not afraid to be between the dots to make a play."
The Big 10 Tournament starts March 16. Minnesota is first in the conference standings.
Neal Pionk, D, Minnesota-Duluth
The right-shot defenseman is a 21-year-old sophomore. He's tied for 10th among NCAA defensemen with 28 points (seven goals, 21 assists) in 34 games and is a plus-18.
Starman said Pionk's best quality is his slap shot, which he said was reminiscent of Montreal Canadiens defenseman Shea Weber.
"He's a legitimate threat to score every time he's on the ice, that's how good his shot is," Starman said. "He's good in his own zone. But when you watch him, what stands out is how good his shot is, and he can score with it. He's got a Shea Weber quality to him with the shot. Just got a missile."
UMD hosts Miami in a best-of-3 NCHC tournament quarterfinal series March 10-12.
Michael Vecchione, RW, Union
Vecchione (5-10, 195) is tied for second in the NCAA with 26 goals in 34 games, and his 58 points are third. He's tied for the NCAA lead with six game-winning goals and four shorthanded goals. The 24-year-old senior is in his second season as captain.
"I like his game," Starman said. "He's athletic, got a good nose for the net. Doesn't overplay the game. Takes what's given to him and he makes something out of it. The beauty of him is he's very well coached, high hockey IQ and the hands and feet to match it. I think he's like [Canadiens forward] Brendan Gallagher but he's more offensive at this level. Just another one of those slightly undersized guys that plays so hard and gives you everything he's got, so you can't discount the fact that that could translate to the next level."
Union will host Princeton in a best-of-3 ECAC tournament quarterfinal series March 10-12.