Cruz sustained the injury while attempting to catch a touchdown pass during Sunday night's 27-0 loss to the Philadelphia Eagles. He had to be carted off the field, at which point Beckham wanted to say something to his teammate.
"I told him, I said, 'Big Bro, I've got you.' I have to step up," Beckham said. "All of the receivers have to step up. The offense. Everybody on the team has to step up. I just told him, I said, 'I got you' because he's had me since Day One. That's the only thing that I feel like is the right thing to do — play for him."
Sunday was just Beckham's second career NFL game after missing the first four due to a hamstring injury. Last week against Atlanta, he caught his first career touchdown pass. In the loss to the Eagles, the rookie had two catches for 28 yards.
Cruz was New York's leading receiver each of the last two years. He had 23 catches for 337 yards and a touchdown in six games this season.
Beckham was the No. 12 pick in the 2014 NFL Draft and was third-team AP All-America last season at LSU.
The Giants (3-3) play the Cowboys (5-1) in Dallas on Sunday.
- Molly Geary