The player exposure requirements are different for skaters and goaltenders. While the required one defenseman and two forwards must be under contract for 2017-18 (in addition to games played thresholds), the goaltender can be under contract for 2017-18 or a restricted free agent.

To prevent teams from simply exposing RFA-status goaltenders that they have no intention of retaining in the first place, an additional expansion clause requires the team to tender a qualifying offer on the RFA goalie prior to submitting their protected list.

If the Sabres want to expose Lehner as part of the player exposure requirements, they have to tender a qualifying offer of $2.225M to him prior to submitting their list on June 17, 2017.