Omark had two assists in 13 games with the Sabres. The 2007 fourth-round draft pick was regarded a disappointment after Buffalo gave up a conditional sixth-round draft pick in a trade with Edmonton on Dec. 19.
Overall, he has eight goals and 32 points in 79 career games.
Should he clear waivers, Omark would have an opportunity to develop with the Sabres' AHL affiliate in Rochester.
The Sabres also demoted two rookies, centre Phil Varone and defenceman Chad Ruhwedel, to Rochester.
The moves were announced Friday, a day after Buffalo closed its pre-Olympic break with a 3-2 loss at Ottawa.