1. OG Isaac Seumalo
The number one underrated player on the Pittsburgh Steelers roster belongs to a player who has yet to take a snap in a Steelers uniform: Isaac Seumalo. Playing offensive guard, Seumalo wasn't a particularly well-known player with the fanbase when he was signed during the 2023 offseason. But don't mistake that for thinking that he's not good.
Seumalo was part of a spectacular offensive line that Andy Weidl helped build in Philadelphia before coming to Pittsburgh. While he was often overshadowed by All-Pros playing next to him like Jason Kelce and Lane Johnson, Seumalo has been 'Steady Eddy' over the years.
In 2022, Seumalo graded out as the 10th-best guard in the NFL, according to Pro Football Focus -- just behind Dallas Cowboys All-Pro, Zack Martin. According to PFF, Seumalo allowed just one sack on 753 pass-block snaps (1,350 total).
Seumalo is approaching 30 years old, but he's still in the thick of the prime of his NFL career as an offensive lineman. Guards don't often get a lot of attention unless you have one of the very best in the league, but Seumalo has excellent film with the Eagles and should be a huge asset for the Steelers if he can stay healthy. He might already be one of the best players on the team, and fans don't even realize it yet.