At this point the team will have no choice but to sign Clark and XSF! Clark is the only one they have that can play LT at an Ok level for the NFL unless, by some miracle, DB returns. And, I'm not holding my breath for that to happen any time soon! As for XSF, they could use Mancz to start there but then they have no experienced depth him.
I don't see any "answers" coming "from within" this season unless DQ gets promoted from the PS and starts playing, but I don't really see that happening unless one of the OG's is lost for the season. Even then I don't know how much playing time he would get with Mancz the likely starter and Fuller as a backup. I've stated before in other threads that I think Davenport and Fuller need at least an off season of conditioning to be able to play at an NFL level. Both have been used sparingly as extra blocking TE's from time to time to give them some experience and I expect that to continue this season.
This O-line situation really has only 3 answers:
1.) Get Brown back in here now and hope you can go through the rest of the season with no O-line injuries. Move Clark to RT and continue to develop Davenport, Fuller, DQ, etc...
2.) Trade Brown for draft pick(s) and really hope you can go through the rest of the season with no O-line injuries. Keep Clark at LT and continue to develop Davenport, Fuller, DQ, etc... Then package draft picks to move up to 1st or 2nd round and get the best LT/RT available in the Draft and go from there.
3.) Do nothing with Brown and maybe try to negotiate with him in the off season or trade him for whatever you can get. Draft an O-lineman in the 3rd round or lower and hope that an off season of development for Davenport,
Fuller, DQ, etc... pays off!