You get to add one

[*ochocincos*]

At this point, there's probably no full-fledged starter I'd look to bring in based on who is available.

I could definitely lean WR since the drop off after Boyd is pretty big.
If something happens to Boyd, Higgins, or Chase, that replacement WR is going to STRUGGLE.
Will Fuller is probably on most people's minds, but he fragile.
I personally like DeDe Westbrook.
Westbrook also offers quality PR ability that some of the other veteran WRs don't.

I could also lean Ereck Flowers.
Dude has shown he's just a mediocre OT but a rather good OG.
Flowers can definitely push Carman for a starting spot but also offer great versatility if he's the first guy off the bench.