NASHVILLE, Tenn. -- It was troubling that Tennessee Titans rookie wide receiver Dorial Green-Beckham didn’t finish a route and allowed Panthers free safety Kurt Coleman to make a third-quarter interception on Sunday.

It was more troubling that Green-Beckham didn’t understand he was largely responsible for the turnover.

With Carolina linebacker Thomas Davis bearing down on him from the left side, Tennessee quarterback Marcus Mariota lofted a poor pass while moving backwards. It floated nearly 30 yards in the air, intended for Green-Beckham who was cutting to the left sideline.

Green-Beckham let up for an instant as he assessed the path of the ball, then failed to drive hard all the way to the sideline. Had he gone hard to the end, Coleman would have had a much harder time angling in front of him and stealing the pass.

The best Green-Beckham managed was a relatively meek wave of his right hand at the ball as it settled in Coleman’s arms.

Dorial Green-Beckham could have done better on Kurt Coleman's interception. AP Photo/Mark Zaleski

“DGB should have been running out a route full speed and was not and the DB was and again, the difference between winning and losing,” interim coach Mike Mularkey said.

But the rookie didn’t realize that, even after some time to contemplate it.

“There’s nothing I could really do about it,” Green-Beckham said.

In discussing the pace of Green-Beckham’s progress, the Titans have often mentioned how he didn’t play football for a year after he was tossed from Missouri and practiced but didn’t play at Oklahoma.

The mental part of his game, nine games into his rookie season, should be further along -- to where he knows he has to drive to the sideline on that route no matter what, and to where he can recognize the consequences of not doing so.