The Patriots swung two trades on Wednesday, both involving the offensive line.
They acquired tackle Korey Cunningham from the Cardinals, and also guard/tackle Jermaine Eluemunor from the Ravens. Cunningham has started two games at tackle, while Eluemunor has seen time at both guard and tackle. Given the Patriots traded for them just a few days before the initial 53-man roster is set, it seems almost guaranteed they will be on it.
So, where does this leave the rest of the offensive line?
Following David Andrews being diagnosed with blood clots in his lungs, Ted Karras seems to be the favorite to take over at center, so the starting offensive line will be (left-to-right) Isaiah Wynn, Joe Thuney, Karras, Shaq Mason and Marcus Cannon. Cunningham and Eluemunor seem to be the backups along with rookie Hjalte Froholdt.
That is eight offensive lineman, but there's always a chance the team could keep nine.
James Ferentz, Dan Skipper and Cole Croston seem to be the next two on the depth chart, and Ferentz is an interesting case given the team really doesn't have a backup center with Karras assuming Andrews' role. This could be a way for him to find his way onto the roster. It's also possible the team tries to bring Croston or Skipper back on the practice squad while it figures out what it has in the two newcomers.
Another thing to consider is if the Patriots believe Andrews has a chance of coming back this season, he would need to be on the initial 53-man roster Saturday before going on IR Sunday. If he's placed on IR prior to Sunday then he cannot return at all. If this is the case, the Patriots likely would keep Ferentz and Croston off the roster with the hope they do not get claimed and then sign them once Andrews goes to IR.
Bottom line, it seems pretty clear the team didn't like its backup options on the offensive line and it went out and did something about it.