DeMelo was selected by the San Jose Sharks in the sixth round (No. 179) in the 2011 NHL Draft after he had 27 points (three goals, 24 assists) in 67 games for St. Michael's in the Ontario Hockey League.

The Sharks signed DeMelo to an entry-level contract on April 20, 2012, after he finished seventh among OHL defenseman in points with 47 (seven goals, 40 assists). In 2012-13, he had 50 points (15 goals, 35 assists) in 64 games for Mississauga.

He spent the next three seasons with Worcester in the American Hockey League, where he had 50 points (seven goals, 43 assists) in 143 games.

DeMelo made his NHL debut in a 6-3 loss to the New York Islanders on Oct. 17, 2015 and got his first NHL point, an assist, in a 4-3 overtime win against the Dallas Stars on Jan. 16, 2016. He scored his first NHL goal on the power play five games later in a 6-1 win against the Colorado Avalanche on Jan. 26 and finished the season with four points (two goals, two assists) in 45 games.

In 2016-17, DeMelo had eight points (one goal, seven assists) in 25 games. In 2017-18, he set career highs in assists (20) and games (63) and had one assist in 10 games in the Stanley Cup Playoffs.

DeMelo was traded to the Ottawa Senators on Sept. 13, 2018, as part of the package that sent defenseman Erik Karlsson to San Jose. He had NHL career highs in goals (four) and points (22) in 2018-19, then had 10 assists in 48 games for Ottawa in 2019-20 before being traded to the Winnipeg Jets on Feb. 18, 2020.

NOTES & TRANSACTIONS

• Traded to Ottawa by San Jose with Chris Tierney, Rudolfs Balcers, Josh Norris, San Jose's 1st-round pick in 2019 or 2020 NHL Draft, a 2nd-round pick in 2019 NHL Draft and two conditional picks for Erik Karlsson and Francis Perron, September 13, 2018.
• Traded to Winnipeg by Ottawa for a 3rd-round pick in 2020 NHL Draft, February 18, 2020.