Born in Russia, Jaskin was eight months old when his family relocated to the Czech Republic after his hockey-playing father, Alexej, joined a club there. Raised in the Czech Republic, the younger Jaskin would represent his adopted homeland internationally.

Jaskin started his career in HC Vsetin's youth programs and eventually transferred to Slavia Prague, making his debut for the club in the Czech Extraliga in 2010-11 at age 17. He had three goals and 10 points in 33 games, making him the second highest scorer in the league among junior-aged players. The St. Louis Blues selected Jaskin in the second round (No. 41) of the 2011 NHL Draft.

After spending the 2011-12 season with Slavia Prague, Jaskin was selected by Moncton of the Quebec Major Junior Hockey League in the 2012 Canadian Hockey League Import Draft. Jaskin played 51 games with Moncton in 2012-13, leading the club with 46 goals and 99 points and finishing fifth in the league in scoring. He was named to the QMJHL First All-Star Team.

The Blues signed Jaskin to an entry-level contract on April 3, 2013 and assigned him to their American Hockey League affiliate in Peoria. St. Louis called him up six days later, and he made his NHL debut April 16, 2013, against the Vancouver Canucks, one of two League games he played that season.

A big, strong player (6-foot-2, 217 pounds) with a mean streak who is difficult to knock off the puck, Jaskin began the 2013-14 season in the AHL before being recalled to the Blues for a Dec. 23, 2013 game against the Calgary Flames. Jaskin got his first NHL goal (and point) in his next game, five days later against the Chicago Blackhawks.

He played 18 games for St. Louis in 2013-14, then had 13 goals (including four game-winners) in 54 NHL games in 2014-15. Jaskin made his Stanley Cup Playoff debut April 16, 2015, against the Minnesota Wild.

Jaskin had the first multipoint game of his NHL career Oct. 18, 2015, against the Nashville Predators. His first NHL playoff goal was the game-winner in his first postseason appearance of 2016, a 4-1 victory against the Dallas Stars on May 7.

NOTES & TRANSACTIONS

• QMJHL First All-Star Team (2013)
• Claimed on waivers by Washington from St. Louis, October 2, 2018.