His role appeared to be as a selectable character for the multi-player function the beta provided in which he piloted an arwing suggesting that he was intended to be a new team member to Star Fox. Both him and Fara Phoenix were later removed.
It is possible that fellow scrapped character Fay replaced him in the final beta.
There are some theories as to which character Saru became in the official series: Since he was a primate, it could be very easily speculated that the concept for his character was adapted into the character Dash Bowman in Star Fox Command for the Nintendo DS handheld system. The fact that, in one of Command's endings, he looks similar to Andross, his grandfather, lends credance to this idea.
There is also a pilot in Star Fox 64 who, while presumed nameless, pilots a vessel called the Sarumarine which may indicate that this character may be the Saru. However, whether it is just his name or if he is the real Saru is unknown granted if this may be true or not.