FLORHAM PARK, N.J. — New York Jets rookie wide receiver Omar Cooper Jr., one of the team’s three first-round picks, was placed on injured reserve Saturday with a sprained ankle, a source told NFL Network’s Ian Rapoport.

Cooper, who played only four snaps in the Week 1 win over the Tennessee Titans, is expected to return after his four-week IR stint. He is eligible to play Oct. 18 against the New England Patriots.

The Jets now have two wide receivers on injured reserve — Cooper and Tim Patrick — leaving them with only four receivers on the active roster for Sunday’s game against the Green Bay Packers at MetLife Stadium.

Chances are the Jets (1-0) will lean heavily on their tight ends in the game plan. They have five on the roster and actually used all five on one play in the 23-10 win over the Titans.

Cooper, drafted 30th overall out of Indiana, made a quick impact in his debut. On the opening possession, he caught a short pass, broke several tackles and turned it into a 30-yard play, setting up a touchdown. After that, he left the game.

He didn’t practice all week and was ruled out Friday.

Beyond starters Garrett Wilson and Adonai Mitchell, the Jets have Isaiah Williams and Arian Smith at wide receiver. Williams and Smith were targeted only once apiece last week, with Smith dropping his only chance.

For depth purposes, the Jets signed veterans Sterling Shepard and Tyler Johnson this week to the practice squad, but neither is expected to be elevated for Sunday’s game.