With the Steelers' 28-21 win over the Texans on Sunday, they improved to 3-0 for the first time since 2010, which is just the third time they've reached that feat in Tomlin's tenure (2007,2010 and 2020).
With a win on Sunday in Nashville, the Steelers would start the season 4-0 for the first time since 1979 and will be just the fourth time in franchise history. The Steelers won the Super Bowl in 1979, as they did in 1978 as well when they started the season 4-0. The other season in which they started the season 4-0 was in 1973, which ended in a Divisional Round playoff loss to the Raiders.
Going into the season, the Steelers and Titans were both touted as premier teams in the AFC and both have a 3-0 record to start the season, but the two teams haven't beaten anyone of significance thus far. The Steelers' three opponents they've beaten have a combined record of 0-9 (Giants, Broncos and Texans), while the Titans' three wins came against teams with a combined record of 1-8 (Broncos, Jaguars and Vikings). The Titans' three wins have come by a combined six points.
It's hard to get a real good indication of where both teams stand in the hierarchy of the NFL, but after Sunday's game, we should have a better idea.