Mike Shanahan initially “was very upset” over the second-quarter interception. (Richard Lipski/Associated Press)

Redskins coach Mike Shanahan said that quarterback Robert Griffin III wasn’t to blame for the interception that killed a potential scoring drive in the second quarter against the Detroit Lions on Sunday.

On first-and-10 from the Detroit 19-yard line, Griffin rolled to his right, looking for an open receiver with defensive end Willie Young in pursuit. Young got a hand on Griffin and started pulling him down from behind when the quarterback chucked the ball downfield, attempting to get it to wide receiver Pierre Garcon around the 10-yard line.

Lions defensive back Chris Houston came back to the ball and intercepted it.

After the game, Griffin explained what happened.

“Coming down, I didn’t get to see the throw I got pulled and tackled on. I thought I saw Pierre coming right back down the stem towards me on the sideline,” Griffin said. “And when I watched it on the big screen, he actually stepped out of bounds and the corner behind him kept coming down. Another play where if you make the play, it’s a great play, but if you don’t, it’s a bad play. And it was a bad play.”

Shanahan said on Sunday that he believed Griffin was pressing because his team was behind and needed a play.

But on Monday, after re-watching the game, the coach changed his opinion.

“That was not his fault,” Shanahan said. “I was very upset during the game. I thought he just kind of threw it haphazardly, and really it was a great throw. It just didn’t work out that way. I’m not going to go through the blame, but as I said after the game, I thought it was just a mistake, and it was a good throw.”

Griffin’s other major miscue of the game came when he dove head-first and fumbled at the end of a 21-yard run rather than sliding feet-first.

Shanahan explained that the right call was made because Griffin had dove and not slid. The coach said after the game that he has seen quarterbacks use both methods and that all he cares about is Griffin taking care of the ball.

On Monday, Shanahan said Griffin has and will continue to work get better at sliding.

“You practice his sliding. He actually practices it at practice. Not that he’s a great slider, but he’s getting better. He didn’t slide very much in college. He’s gotten better at it in practice. He’ll continue to get better as he does it.”

Have a Redskins question? E-mail Mike Jones at mike.jones@washpost.com with the subject line “Mailbag question” for him to answer it in The Mailbag on Tuesday.

What’s ahead:

● Sunday’s opponent, the Oakland Raiders, plays at 8:40 p.m. tonight in Denver. Here’s a preview of that game.

More on the Redskins and NFL:

Shanahan: Two key calls were correct | Pleased with offensive balance

Cofield: Defense isn’t playing well enough to win | Forbath hopeful for Oakland

Chester: RGIII good enough to win | Garcon: He’s still not himself

D.C. Sports Bog: Smoot: RGIII a ‘brat,’ Shanahan ‘Red Lobster’ | More Bog

The Early Lead: Cardinals’ Johnson loses part of finger | More NFL

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