Posted by ESPN.com's James Walker
The Browns have agreed to terms with first-round pick Alex Mack, the team announced Saturday. He was the No. 21 overall selection in April's NFL draft and is expected to compete for the starting job at center against veteran Hank Fraley.
Cleveland also released linebacker David Holloway to make room for the move.
As Cleveland gets into its second day working with rookies, the Browns still have three second-round picks not under contract. Those players are linebacker David Veikune and receivers Brian Robiskie and Mohamed Massaquoi.
The Browns will begin training camp with their full squad on Aug. 1.