I think all players are under contract until June 30.If Edmonton advances (likely) and Toronto doesn't (again likely), can Auston Matthews play for Oilers ? Its not a trade. He's near end of contract. Can Oilers sign Auston ? Will be a great help to Edmonton. After all there's no salary cap in playoffs. He might as well if TO gets eliminated. I've heard of teams signing other players during the playoffs. I am not aware of any rules that would prevent this from happening.