TSN's Chris Johnston has reported that the Leafs intend to "run it back" with their main 4 players, which includes Marner, however it is expected that it will be his final year in Toronto, as the Leafs will let him walk in free agency.
The Leafs recently signed Nylander to an 8 year contract worth $11.5M per year, and Tavares has expressed interest in remaining with Toronto long-term. With Matthews being paid big dollars, the Leafs simply have no room for Marner to fit under the salary cap.
As much as Leafs' fans want Marner signed long-term, the reality is that the Leafs, knowing they can't afford him, should not risk losing him for nothingduring free agency, and will need to try and trade him by the trade deadline. Teams would be willing to pay a high price for Marner, and the Leafs need to capitalize on that.