While the Bengals weren't happy enough to keep Fui Vakapuna on the team's 53-man roster in early September, they've signed him to the team's 53-man roster on Tuesday. However, that's yet to be announced as of this post, but his agent confirmed nonetheless. That left the Bengals with 54 guys on the roster, which is, you know, bad. To make room, the Bengals elected to terminated "the contract of long-time backup offensive lineman Scott Kooistra."
Here's where I think signing Fui Vakapuna makes sense.
Vakapuna brings you versatility. With Bernard Scott and Jeremi Johnson coming off injuries, the Bengals are in optimistic flux. If Jeremi Johnson can't go, throw Vakapuna in there. If Bernard Scott can't go, then Brian Leonard probably goes. But Vakapuna could be a second backup running back. If Bernard Scott and Jeremi Johnson can't go, wham. You have Vakapuna, who could play both spots. Not at the same time, of course. Someone like that would be drafted at least in the third round.
Along with being able to play fullback, Vakapuna is also an accomplished running back, scoring 18 touchdowns (14 on the ground) in four seasons (42 games) with the BYU Cougars. He averaged 4.7 yards-per-rush in his collegiate career. For the sake of a pointless (now) argument, Chris Pressley was a nasty fullback, and if we're looking to have a backup fullback in the category of "oh boy, Johnson is hurt", then Pressley is obviously your guy... if he wasn't already with the Tampa Bay Buccaneers. But Pressley carried the football 25 times in his career at Wisconsin and scored one touchdown. If the Bengals were in desperate need of a running back (ala against Chicago Bears), Pressley doesn't give you much. Vakapuna gives you more.
I would go so far as to say that even if Pressley were with the Bengals practice squad, Fui Vakapuna is still signed with the Bengals. If Marvin Lewis likes anything (besides busted garage gates at five in the morning), he loves versatility with his players. And since Vakapuna brings that by being able to play fullback and running back, it makes sense to have one guy to fill in both roles while guys work on recoverable injuries.