Butler punted for the Steelers last season, and two-time Pro Bowler Brian Moorman couldn't unseat the second-year man as the two competed for the job. But neither punted particularly well in four preseason games, and the Steelers signed Mesko, who had been released after averaging 44.3 yards per punt in three seasons with the Patriots.
Butler averaged 43.8 yards per punt in 2012. He was also the holder on field goal and extra-point attempts.
In addition to signing Mesko, the Steelers tried to upgrade their special teams by adding Blake.
Blake made the Jaguars as an undrafted free agent last season and led the team with 12 special teams tackles.
The Steelers have now made three moves since the final cut-down on Saturday. They signed offensive lineman Cody Wallace on Sunday and released John Malecki. Wallace, a guard and center, played eight games with the Buccaneers last season.