Great prospect but I just would not go that way personally. It's a really hard position to justify using a top 25 overall pick. I am all for Sullivan coming back while having Blythe behind him
and also drafting a center somewhere. But not before the 3rd round. Just me. Look at a year ago when they wanted to get Groy from Buffalo (who was an UFA so would have cost them nothing) as a RFA and then found Sullivan later.
Also making it harder to use a top 25 pick there is having no 2nd this year. Center is a very valuable spot and going from Barnes to Sullivan made a world of difference for this offense. But I think Sullivan has another year in him while they improve the depth behind him. Maybe consider a late 2nd rounder in 2019 or pursue another RFA like they did with Groy if they don't have someone to their liking a year from now.
Just my opinion.