Klimchuk, 23, has appeared in 17 games with the AHL’s Stockton Heat in 2018-19, collecting three goals and five assists. The fourth-year pro has totaled 44 goals and 56 assists for 100 points in 204 career AHL games with Stockton and Abbotsford.
A first-round selection (28th overall) by Calgary in the 2013 NHL Draft, Klimchuk has played one career NHL games with the Flames, making his debut on Feb. 19, 2018.
Nielsen, 22, has three assists in eight games with the AHL’s Toronto Marlies this season. In his third pro season, Nielsen has registered 20 goals and 50 assists for 70 points in 152 AHL games, all with the Marlies. He was also a member of Toronto’s Calder Cup championship team in 2018.
Nielsen was selected by the Maple Leafs in the third round of the 2015 NHL Draft.