Mittelstadt (upper body) will not play in Tuesday's tilt versus the Islanders, Lance Lysowski of The Buffalo News.
Mittelstadt will hope to be cleared to return by Thursday's game against Ottawa. The 23-year-old will be withheld from a fourth consecutive contest due to an upper-body injury. His last NHL point was logged as an assist in a 3-1 victory over Arizona on Jan. 29.