SAN DIEGO -- Melvin Gordon's 44-yard touchdown catch in the San Diego Chargers' preseason opener against the Tennessee Titans was a good example of what ailed the young running back during his rookie season.

A year ago, Gordon would have still been in the backfield contemplating who to block in pass protection.

But fast forward to his second season, Gordon quickly recognized San Diego's offensive line had everyone accounted for and leaked out to the flat.

Tennessee linebacker Avery Williamson was late picking up Gordon in coverage, and by the time he tracked down the Wisconsin product Gordon had bowled his way into the end zone.

Philip Rivers mentioned after the game that Gordon will get more touches like that when he plays fast and is decisive in his reads, both as a runner and in pass protection.

"When you're in there for your first game or whatever the case may be, you're kind of sure on protection, but you're really kind of unsure," Gordon said. "You're probably looking at guys that you're probably not even supposed to look at. That's (snaps his fingers) is all it takes sometimes. You're just out a second faster, and sometimes that's all you need."

Gordon said it's night and day from his rookie season to his second year, in terms of knowing his assignment and how to read the defense.

"I remember the first play I ran (my rookie year) I was just thinking about how fast the linemen were," Gordon said. "I didn't even look at my read. I'm just looking at the linemen the whole time I'm running the play.

"This time I was just comfortable and stuck to my reads. I was obviously nervous the whole trip there, but I just told myself that you're going up against some great players every day in practice and you've had a whole season, so just be calm, read your reads and follow your lineman."

Gordon said he was excited to finally get into the end zone for the first time as pro after being held without a touchdown his rookie season.

"I haven't been in there for a while, so it felt good," Gordon said. "Even though it doesn't count and it's still preseason, it still felt good to get in there. It kind of makes you want to get in there more when you get that feeling."

Injury update: The Chargers placed receiver Stevie Johnson (knee) and defensive tackle Sean Lissemore (shoulder) on injured reserve Monday, and also waived cornerback Carrington Byndom. With the vacant roster spots, the Chargers added defensive tackle Kamal Johnson, along with linebackers Zack Hodges and James Vaughters. ... Receivers Tyrell Williams (quad) and Travis Benjamin (hamstring), along guard Orlando Franklin (ankle) and defensive end Tenny Palepoi returned to practice on Monday. Center Spencer Pulley, cornerback Greg Ducre, receiver Javontee Herndon, receiver Ricardo Richardson, linebacker Jatavis Brown, linebacker Chris Landrum, defensive lineman Zamir Carlis did not practice. ... Center Chris Watt remains on the physically unable to perform list.