Stovall has played in 71 games with 11 starts after being selected in the third round of the 2006 draft by Tampa Bay. He has 52 receptions for 668 yards and three touchdowns. He spent five seasons with the Buccaneers before joining Detroit in 2011. He entered the NFL as a receiver before moving to tight end.
Spach spent nine days on Jacksonville's roster. He played Sunday against Houston.
The Jaguars also signed guard Austin Pasztor to the practice squad. Pasztor, a 6-foot-7, 308-pound Canadian, played college football at Virginia. He signed as a rookie free agent with Minnesota in May and was waived in late August.