We do need to extend Karras.Froholdt has the skills to start at LG...he would probably be average his first season there...which is good enough with Wynn and an improved Karras on either side...or Andrews at C.
Mason is a top 5 G in the NFL when healthy...he’s not going anywhere.
I’m more concerned about RT. Cannon’s level of play is declining due to age and injuries. Newhouse is the same age I believe and should only be a backup. Cajuste is probably not going to play much in 2020 with trying to recover from his quad situation.