I hope we sign Mangold, if we're comfortable with his injury status. He'll bring leadership that we've not had since Birk's retirement. I hesitate to commit to Siragusa, as he is too much of an unknown. The last time we threw a 4th round rookie into that role it was catastrophic (Gino).
Urschel and Jensen had their shot at a starting spot last year and neither impressed. They also had opportunities at times to fill in and they did not step up. Remember - even if we sign Mangold, we still have another starting slot to fill on the line. So even if we have faith in these guys, one of them is going to have to step into a starting role (likely at LG, if we move Lewis out to RT) ... unless we sign an additional FA for the o line