The Giants have lost their opening five matches of the current NFL campaign, with Manning throwing a league-high 12 interceptions including three in the fourth quarter of Sunday's 36-21 loss to the Philadelphia Eagles.
"The type of person he is, he takes a lot of that blame, but that's not the way it is. It's everyone. It's the receivers. It's the offensive line," Cruz told reporters.
"It's everyone that's to blame for some of these losses and the things that have happened out there. It's a full team effort, not just one guy. You can't just put the blame on one person."
The Giants will face the Chicago Bears on Thursday as they look to put an end to their losing streak.