There has been constant advancement in football equipment over the years, from lighter shoulder pads to safer helmets. Shoes can be custom-designed to fit a player’s cleat preference. Undergarments wick away sweat while still keeping the player warm.

For the speediest players, though, there is one equipment advance that would be particularly useful but has yet to find its way into the mainstream: a rearview mirror.

In its absence, players must improvise. When Giants receiver Victor Cruz ran a short out pattern in the first quarter last Sunday against the Dallas Cowboys, he caught the ball near the sideline, received an important block from Hakeem Nicks to open a gap along the edge of the field and accelerated away from the clot of defenders near the Giants’ 45-yard line.

As Cruz was near the Dallas 25, he did not look over his shoulder — that would slow him down — but instead glanced up at the large video board that sits on the rim of MetLife Stadium. The board was showing the play live, and Cruz was able to see exactly where two defensive backs were behind him.