Kreps played in 76 games for Florida as a rookie this season, finishing with eight goals and 17 assists.
Belak, acquired in a trade with Toronto on Feb. 26, played in the Panthers' final 17 games.
Kreps was Florida's third selection, No. 38 overall, in the 2003 draft.
Belak completed his 11th NHL season, having played for Calgary, Colorado and Toronto. He has piled up 1,108 penalty minutes.
Florida also signed defenseman Luke Beaverson of Alaska-Anchorage. He was drafted in the seventh round by the Panthers in 2004.