He was slated to be the team's starting left tackle.
Kentucky is hoping for a big season from its football program this fall, but the Wildcats will now be without a starting offensive lineman.
Left tackle Cole Mosier, who started 10 games last season, tore his ACL in a preseason scrimmage over the weekend and will miss the entire upcoming season.
Mosier redshirted in 2013 and isn't eligible for a sixth season, so his Kentucky career is over.
This is a rough blow for a unit that is considered one of the better offensive lines in the SEC.
For his career, Mosier appeared in 33 games, making 13 starts.
Kentucky opens up its 2017 season on Saturday, Sept. 2 against Ole Miss.