Callahan, 22, made his NHL debut on March 25 against the Columbus Blue Jackets. He was second on the Grand Rapid Griffins of the American Hockey League with 26 goals and fourth with 44 points in 70 regular-season games.
Callahan was a sixth-round pick (No. 180) in the 2009 NHL Draft.
Nestrasil, 23, had 16 goals and 36 points in 70 games for the Griffins. He was a third-round pick (No. 75) in 2009.
You can be hyped all you want, but his game will speak for itself. He's obviously going to be a great player so we've got to make sure we keep an eye on him. Whether it's his first game or his 1,000th game, our job is to take care of business, shut him down.
— Blues defenseman Alex Pietrangelo on facing ballyhooed Oilers rookie Connor McDavid, who is making NHL debut in St. Louis
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