The team also waived receiver Chastin West, quarterback Nathan Enderle, linebacker Nate Bussey, running back DuJuan Harris, cornerback Mike Holmes, offensive tackle Dan Hoch and linebacker Donovan Richard.
Youboty started five games for Jacksonville last season. He spent his first five seasons in Buffalo, where he played in 50 games.
The Jaguars have 82 players on their roster and need to trim seven more before the league's Monday afternoon deadline. Some of those could be injury-related moves.
Linebacker Clint Session (concussion) and defensive end John Chick (knee) are likely to end up on the physically unable to perform list. And reserve tight end Matt Veldman will go on injured reserve after suffering a knee injury Thursday night against Baltimore.
Monroe missed the past two exhibition games after sustaining a concussion in practice. Coach Mike Mularkey says Monroe passed his concussion test Friday and was cleared to practice. He was working with the starting unit Saturday. Guard Will Rackley also was back in a limited capacity after missing much of training camp with a high ankle sprain.
Like Rackley, Smith missed all three preseason games. He injured his groin early this month.
Information from The Associated Press was used in this report.