2007-08: Greg McKegg was chosen second overall by the Erie Otters at the 2008 OHL Priority Selection.
2008-09: In his OHL rookie year for the Erie Otters, McKegg scored 8 goals and added 10 assists for 18 points in 64 games. Appeared in 5 playoff games for the Otters, picking up 2 goals and 1 assist. Played for Team Canada at the 2009 World Under-17 Hockey Challenge where he earned a gold medal.
2009-10: McKegg had a breakout season for the Otters. Appearing in 67 games for that club, he scored 37 goals and assisted on 48 others for 85 points. Went from a -13 rating in 2008-09 to a +18 rating in 2009-10. Suffered knee strain in preseason and spent the rest of the year working to get his speed back. Played on top line with Zack Torquato and Mike Cazzola. Played in four playoff games for the Otters, picking up 2 goals and 1 assist. McKegg was selected 62nd overall by the Maple Leafs in 2010. He was ranked 73rd by ISS and 66th by Central Scouting for North American skaters.
2010-11: McKegg made his pro debut, appearing in two games with the AHL Marlies, after leading the Erie Otters in points in his third OHL season. McKegg's 49 goals tied Sarnia's Nail Yakupov for third most in the OHL. In 66 games with the Otters he was +35 and along with his goal scoring had 43 assists and 35 PMs Erie faced defending Memorial Cup champion Windsor in the first round of the playoffs and McKegg scored 4 goals with 1 assist and was +2 with 12 PMs as Erie took the Spitfires to seven games.
2011-12: McKegg returned to Erie for his fourth OHL season after attending camp with the Maple Leafs. He was obtained by London in an OHL trade deadline deal in January and skated in 30 regular season games and both the OHL and Memorial Cup playoffs for the Knights. In 35 games for last-place Erie prior to the trade, he scored 12 goals with 22 assists and was minus-39 with 32 penalty minutes. He scored 19 goals with 22 assists and was plus-five for London during the regular season. McKegg was plus-five with 4 goals and 7 assists in 15 playoff games as Midwest Division champion London captured the OHL title. The Knights reached the Memorial Cup championship game, falling to host Shawinigan, 2-1 in overtime, and McKegg had 1 goal with 4 penalty minutes in five games.
2012-13: McKegg skated for the AHL's Toronto Marlies as a 20-year-old in his first pro season. Seeing limited ice time early in the year and a healthy scratch at times with the surplus of forwards due to the NHL lockout, he appeared in 61 games and scored 8 goals with 15 assists; finishing +4 with 22 penalty minutes. Toronto finished first in the North Division and reached the second round in the AHL playoffs. McKegg played in all nine playoff games. Two of his three goals were scored on the power play and he was -2 with 3 assists and 10 penalty minutes.
Capable of lining up at center and wing, McKegg is an offensive catalyst with a good mind for the game. He’s a natural goal scorer who can find numerous ways to bury the biscuit. Not overly physical, but also doesn’t shy away from contact. He has deceptive hands and the ability to slip through tight areas. Game-to-game consistency and strength are areas of weakness in McKegg’s game currently.
McKegg will return to a top-six role with the Toronto Marlies in 2013-14