Marner has talked to several teams about a possible offer sheet, reports Aaron Portzline of The Athletic. The list includes Columbus.
Marner was given a qualifying offer by the Leafs on Tuesday.
Marner's contract negotiations with Toronto could be contentious, reports Darren Dreger of TSN.ca. He may test the market before signing an extension with Toronto.
Marner's contract extension is the Leafs' "priority one" going forward, says Maple Leafs' general manager Kyle Dubas.
Marner posted an assist in Monday's 3-2 win over Boston in Game 3 of the best-of-seven series.
Marner scored a pair of goals -- one coming on a penalty shot -- in Thursday's 4-1 Game 1 victory over Boston.
Marner scored his 26th goal of the season in Thursday's 3-1 loss to Tampa Bay.
Marner dished out two assists, one on the power play, in 20:06 of ice time in Wednesday's 5-4 loss to Chicago.
Marner scored a goal and added an assist in Saturday's 5-2 win over Buffalo.
Marner scored a goal and added two power-play assists in Wednesday's 6-2 win over the Oilers.