He hasn't played yet this season after suffering a torn ACL in OTAs. He was activated from the physically unable to perform list on Monday.
Running back Melvin Gordon is also active after suffering a minor knee injury of his own in last weekend's win over the Baltimore Ravens.
Henry, 24, caught 45 of 62 targets for 579 yards and four touchdowns during his sophomore campaign in 2017. The second-round pick of the 2016 draft caught eight touchdowns as a rookie.
He'll represent a significant upgrade over the Chargers' tight end combination of Antonio Gates and Virgil Green, who combined for just 47 catches, 543 yards, and three touchdowns in the regular season.