Vainonen, 19, spent his first season with the Kingston Frontenacs in the CHL, and the native of Finland was fourth among defencemen with 22 points. He also was the captain of Finland's team at the 2012 U-18 World Championships.
He was the Predators' sixth selection in the 2012 draft at No. 118 overall in the fourth round.
You get the right the whistles at the right times, you can leave him out there. He's a beast when it comes to being on the ice. I thought [Saturday] he was a big man. That first period, he did that lateral cut and it was like three bowling pins bounced off him. There's not too many guys that can do that.
— Capitals coach Barry Trotz on Alex Ovechkin, who enters February tied for the NHL lead in goals