Gregor, 25, was originally drafted in the 4th round (111th overall) in the 2016 NHL Entry Draft by the San Jose Sharks. He has bounced around between the NHL and the AHL over the past several seasons, but finally stuck in the NHL last year, playing 57 games for the Sharks, notching 10 goals and 17 points over that span. Gregor has dressed in 178 games, racking up 26 goals and 51 points.
This is likely the first of a few PTOs that are expected in Toronto. I'd imagine we'll see at least one PTO offered on defense as well. As far as Gregor goes, even if he fails to earn a roster spot with the Leafs out of camp, he may be able to earn himself a roster spot with the Leafs' AHL affiliate, the Toronto Marlies.