The New England Patriots have added a number of impact players in free agency. But they will also face a number of changes on the offensive line.

New England lost offensive guard Joe Thuney when he inked a lucrative deal with the Kansas City Chiefs. The Pats will be making a change at center, as well.

Ted Karras is returning to New England after spending a year in Miami with the Dolphins. It looks like he will be the starting center, with Doug Keyed of NESN reporting the Patriots will not be re-signing veteran offensive lineman David Andrews.

Andrews started in 12 games for the Patriots this past season after missing the entirety of the 2019 season due to blood clot issues. He was not quite the Andrews of old.

The 28-year-old had one of the best Pro Football Focus grades (84.7) among offensive linemen in 2017. But that number slipped to 67.7 in 2020. Still respectable, to be sure, but not as elite as past years.

Granted, Karras had a lower PFF grade (65.3) in 2020. But there is a sense of familiarity in New England, and Andrews might also be slightly more inexpensive.

Things will be different in the trenches. But the Pats have made an interesting pivot. Karras has experience playing center in New England. Bill Belichick also orchestrated a trade for former Las Vegas Raiders offensive tackle Trent Brown, who made the Pro Bowl in 2019 before playing just five games in 2020 due to a variety of physical setbacks.

The Patriots have mostly made headlines for their spending in the first two days of free agency. But it will be interesting to see what the subtle changes up front mean for the team's offense going forward.