Pro Football Focus is a site that basically grades every play a player plays, and they had this to say about him,
"The other player that the TV broadcast was clearly just waiting to run a segment on was Kyle Long, and he justified it and then some, a rarity for those pre-planned player review times. Long dominated from start to finish, earning a +5.7 grade for the game on just 33 snaps, a ludicrously good performance from a guard. He was quick, mobile, strong at the point of attack, playing with good leverage and when he combined with fellow rookie RT Jordan Mills, formed a double team the Chargers’ defensive line couldn’t deal with. It’s only preseason, so I don’t want to get carried away, but he reminded me a lot of Evan Mathis in this game, the player we think has been the best guard in football for a couple of seasons now."