Allen, 26, is a former fifth-round pick of the Steelers back in 2017. He lasted just over two years in Pittsburgh before he was waived coming out of the preseason last year.
The Seahawks later signed him to their practice squad and he was on and off of the unit last year. Seattle opted to waive him and he had brief stints with the Bills and 49ers this season before signing to the Bengals practice squad.
For his career, Allen has appeared in 16 games and recorded one tackle.