The team announced Velasco's signing and Harris' move to injured reserve on Tuesday.
Velasco started his career with the Titans in 2008 as an undrafted free agent out of Georgia and remained with the team through 2012. He played 13 games and made seven starts with the Carolina Panthers last season and started 11 games with the Pittsburgh Steelers in 2013.
Velasco played 49 games and made 19 starts for Tennessee from 2009-12 after spending the 2008 season on the Titans' practice squad.
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