If the cold didn’t provide enough of a mental jolt for Evan Engram, the drops did.

After catching a touchdown pass in four straight games, the Giants’ rookie tight end has corralled just four receptions for 27 yards over the past two games, and he dropped three passes during the Thanksgiving night loss to the Redskins.

“It’s definitely a wakeup call for me and kind of a humbling experience to wake myself up and lock in and do the small things right,” Engram said Friday. “I probably got a little too frustrated and kind of started thinking a little bit too much.”

After the Thanksgiving game, coach Ben McAdoo attributed some of the issues to fundamentals, particularly catching the ball in cold weather.

The southern-bred Engram didn’t want to offer any excuses, but said the change in conditions did call for an increased focus on his technique.

“When it’s a lot warmer, it’s a lot easier to [slack] off on some fundamentals and the ball’s a little more sticky and your hands aren’t cold,” Engram said. “When the weather changes and the conditions affect the game a little bit, definitely gotta focus in on the small things and lock in on those.”

McAdoo put it more simply Friday.

“I believe he needs to catch the damn ball,” he said on the McAdoo Report on Giants.com. “And I believe he will catch the ball.”

Players on all 32 NFL teams will participate in the second year of the “My Cause My Cleats” campaign Sunday. Deviating from the NFL’s typically strict guidelines on footwear, players will be sporting personalized cleats that represent the charity of their choice.

Among the Giants’ causes: Special Olympics (Engram and Davis Webb), Americares for hurricane relief in Puerto Rico (Jason Pierre-Paul and Romeo Okwara), New York Police Department (Eli Apple), Tackle Kids Cancer (Eli Manning) and Covenant House New Jersey (Jay Bromley).

Linebacker Jonathan Casillas will miss Sunday’s game — his fourth missed game of the year — with neck and wrist injuries. Offensive lineman Justin Pugh (back) is doubtful and defensive tackle Damon Harrison (elbow) is questionable. Sterling Shepard (migraines), B.J. Goodson (ankle) and Calvin Munson (quad) have been cleared to play.