Among the reasons undrafted college players are attractive is that they can be signed to a contract without giving up an asset in return, such as a draft pick. It's a good way for a team to beef up areas of need on its prospect list.
NCAA free agents tend to be older than, for example, an undrafted teenager out of the Canadian Hockey League. As a result, they often are further along on their development track and closer to being ready to help at the NHL level.
"You've got to give credit to some of these players that would probably be considered late-bloomers,'' said John Ferguson Jr., executive director for player personnel with the Boston Bruins. "They've continued to work and hone their craft and put themselves in position to have an opportunity to speak to any number of interested suitors.''
Krug was signed by the Bruins on March 25, 2012. He joined them full time during the 2013-14 NHL season and has 301 points (60 goals, 241 assists) in 479 regular-season games.
Although college free agents who develop into stars of Krug's magnitude are rare, good complementary players are available.
Sheary, of the Buffalo Sabres, is an excellent example. After signing with the Pittsburgh Penguins as a free agent out of the University of Massachusetts in 2014, he worked his way up from the American Hockey League to play an important part in consecutive Stanley Cup championships 2016 and 2017. He was traded to Buffalo with defenseman Matt Hunwick on June 27, 2018 for a conditional pick in 2019 NHL Draft.
Here are 15 college free agents who are getting serious looks from NHL scouts this season.
Jack Ahcan, D, St. Cloud State University
Ahcan (5-8, 185) had NHL offers last spring but opted to return for his senior season. The 22-year-old has eight points (two goals, six assists) in eight games this season. He had 34 points (six goals, 28 assists) in 39 games last season.
Brandon Biro, F, Penn State University
The 21-year-old senior (5-11, 161) has been a consistent point producer for Penn State, where he is captain this season. He has 12 points (five goals, seven assists) in nine games and attended development camp with the Penguins in June.
Mitchell Chaffee, F, University of Massachusetts
Chaffee (6-0, 207) drew interest from a dozen NHL teams last spring, according to his coach, Greg Carvel. The 21-year-old junior plays a heavy game in the mold of Noel Acciari of the Florida Panthers, a college free agent signed by Boston from Providence College in 2015.
Patrick Curry, F, Boston University
Curry (6-0, 185) has seven goals in nine games this season. The gritty 23-year-old senior is the captain of a young Boston University team.
Dawson DiPietro, F, Western Michigan University
The 24-year-old senior combines speed with good puck-handling skills. DiPietro (5-11, 185) attended development camp with the Sabres in June.
Josh Dunne, F, Clarkson University
The 20-year-old sophomore (6-4, 210) is tied for the Clarkson lead with 11 points (five goals, six assists) in 10 games this season.
Zach Giuttari, D, Brown University
The 23-year-old senior (6-2, 190) plays big minutes in all situations and is Brown's captain. A good defender, he had 20 points (seven goals, 13 assists) in 34 games last season.
Connor Mackey, D, Minnesota State University
The 23-year-old may be the highest-profile free agent this season. Mackey (6-2, 183) was in demand by NHL teams last season but decided to return for his junior season. His father, David Mackey, played for the Chicago Blackhawks, Minnesota North Stars, and St. Louis Blues.
Ben Meyers, F, University of Minnesota
Meyers (5-11, 190) has six points (one goal, five assists) in 10 games this season. The 21-year-old freshman was a second-team United States Hockey League All-Star last season for Fargo, scoring 33 goals in 59 games.
Marc Michaelis, F, Minnesota State University
The 24-year-old senior (5-11, 187) played for Germany in the 2019 IIHF World Championship. He is the NCAA's active scoring leader with 129 points (56 goals, 73 assists) in 127 games.
Drew O'Connor, F, Dartmouth College
O'Connor (6-1, 190) was a pleasant surprise with 17 goals in 34 games last season as a freshman. The 21-year-old followed with a good showing at development camp with the Bruins in June.
Colton Poolman, D, University of North Dakota
The 23-year-old senior (6-1, 194) is North Dakota's captain for the second consecutive season. His older brother, Tucker Poolman, is a defenseman with the Winnipeg Jets.
Greg Printz, F, Providence College
Printz (6-2, 214) has a lethal shot and is tied for the NCAA lead in goals with nine in 10 games. The 21-year-old junior attended development camp with the Jets in June.
Justin Richards, F, University of Minnesota-Duluth
The 21-year-old Richards (5-11, 190) is a two-time NCAA champ with Minnesota-Duluth. He was named the National Collegiate Hockey Conference's best defensive forward last season. A junior, he is the son of Tampa Bay Lightning assistant coach Todd Richards.
Gustaf Westlund, F, Ohio State University
The 21-year-old sophomore from Stockholm, Sweden, has nine points (five goals, four assists) in nine games. Westlund (6-0, 174) attended Vegas Golden Knights development camp in June.