The Giants can't claim to be surprised that cornerback Janoris Jenkins packed it in when this season went south.

Jenkins warned that this would happen in his very first press conference after signing a five-year, $62.5 million contract in March 2016.

"I could probably improve upon ... stop being lazy at the end of games or whatever," Jenkins said when asked on a teleconference to identify his biggest weakness.

It was a stunning admission by Jenkins, who signed with the Giants after four losing seasons with the Rams, that he let the team's struggles impact his focus.

"Just relaxing, thinking about (passes) not coming to my side," Jenkins said when asked to follow up on his statement. "Just focusing more on the game."

Jenkins later added, "It's not a training thing, it's just a mindset. It's easy to control. Nothing hard. Playing on this level, some things are going to happen. And you've just got to improve."

Jenkins said last season that it was easy to change his mindset when the Giants were winning.

"Yeah, you take a lot of chances and you need a lot of plays," Jenkins said last December of his mindset while playing on losing teams in St. Louis. "Here, you can just play within the scheme, play for your teammates and hopefully bring the energy."

The Giants went 11-5 last season to send Jenkins to the playoffs for the first time in his career. He was one of the most important pieces of a dominant defense, earning a second-team All-Pro selection for his lockdown coverage.

But it's not easy for a Jackrabbit to change its spots, apparently. Jenkins hasn't performed anywhere near that level this season.

More concerning are the signs that Jenkins has checked out as the Giants have fallen to 1-8.

Jenkins failed to show up for the first post-bye practice and didn't even give notification of his absence to coach Ben McAdoo. That unexcused absence earned Jenkins a one-game suspension and, without their best cornerback, the Giants' pass defense got lit up in a 51-17 loss to the Rams.

Jenkins didn't address his teammates or show any public remorse when he returned from his suspension.

"I just didn't show up," Jenkins said of his absence from practice.

That quote could also apply to Jenkins' performance in his return to the lineup in Sunday's 31-21 loss to the 49ers. He allowed an 83-yard touchdown to speedy receiver Marquise Goodwin, but more alarming were the two instances when Jenkins simply turned down tackles. Those plays resulted in a 47-yard touchdown by tight end Garrett Celek and a 21-yard run by running back Carlos Hyde.

Jenkins bolted from the locker room as reporters entered after the game. When reporters tried to stop him, Jenkins said, "I'll be back." Of course, he didn't return. And the Giants are left to wonder when the 2016 version of Jenkins will be back.

Dan Duggan may be reached at dduggan@njadvancemedia.com. Follow him on Twitter @DDuggan21. Find our Giants coverage on Facebook.