Reilly will undergo a procedure on his heart Tuesday and will be sidelined indefinitely.
Reilly (upper body) was designated for injured reserve Wednesday, Stefen Rosner of NHL.com reports.
Per Andrew Gross of Newsday, Reilly (upper body) is out indefinitely, according to the Islanders on Saturday.
Reilly (concussion) will be unavailable against Ottawa on Thursday after missing the game-day skate, Andrew Gross of Newsday reports.
Reilly (upper body) won't be in the lineup Tuesday against Pittsburgh, per Stefen Rosner of NHL.com.
Reilly (upper body) remains day-to-day ahead of Tuesday's game against the Penguins, Stefen Rosner of NHL.com reports.
Reilly (upper body) won't play Saturday against the Rangers, Stefen Rosner of NHL.com reports.
Reilly (upper body) is day-to-day after being injured in Friday's 4-3 win over Buffalo, the team announced Saturday.
Reilly sustained an upper-body injury when he hit his head following a hit in Friday's game versus the Sabres, Stefen Rosner of NHL.com reports.
Reilly has not recorded a point through 10 games this season.