4 biggest holes on the Steelers roster heading into the 2020 season

Inside Linebacker
The inside linebacker room is led by veteran Vince Williams and second-year stand out Devin Bush. These two players anchor what could be one of the best starting linebacker groups in the NFL. Digging a little deeper there is some cause for concern.
The Steelers are likely going to be rolling with Ulysses Gilbert III and Robert Spillane as the two main backups. Gilbert has the most upside with his above-average speed. However, he does not have the strength or play recognition experience yet to be that every-down player.
Robert Spillane is intriguing. It is easy to imagine that if he made an impact, he would no doubt be a fan favorite. Spillane emerged late off the practice squad in 2019 racking up 11 tackles in 8 games.
It is tough to say which young linebacker will stand out but the rotation is likely only going to feature one extra guy. The other will need to carve out more special teams tackles to stay on the team.