Tyler Biadasz looked like a 1st round center who could also play guard in 2018 but he was straight up awful in 2019.
Netane Muti could be a great NFL guard but he's suffered 3 season ending injuries in 4 years.
Alex Taylor is a massive tackle who moves crazy well but he's likely a multi-year project with how raw and unrefined he is.
Since any offensive lineman at this point likely won't start, those are the 3 highest upside guys left imo.