Ferguson is a one year player. FSU fans didn't like him at all. Per the 247 article below, "Ferguson played eight games for the Seminoles and made seven starts. He started the final three games of the season at left guard, but struggled with multiple injuries and inconsistent play. His PFF Grade of 42.6 was the lowest grade among all P4 offensive guards."
https://247sports.com/article/fsu-football-tj-ferguson-offensive-line-transfer-portal-249065104/
This kid is a depth piece for sure. PFF ratings aren't a perfect system and especially for OL, but in no way is he an average player on the OL. PFF grades aren't a team score. Its an individual performance score. Even if he is healthy now and his game picks up it seems very unlikely a rating that was the worst guard in the P4 turns into a decent starter on the OL.
Tom's post above mentioned that he played some Center. If that is the case, I'm guessing that is why the staff brought him in. For that versatility and Center experience. I could see him being the back-up Center. Really what other option do we have there behind Collins? We needed somebody for that spot.
And honestly if we get a serious injury at Center i'm guessing that Petry would likely slide in there and we move a Guard into the starting rotation.
I'm not expecting much from him but we needed Center depth. So I think the pickup makes sense.