The former Swindon player is poised to sign a three-month loan deal with a view of a permanent signing at the end of his loan-spell.
Blades boss Kevin Blackwell confirmed: "We have agreed a deal with Barnsley and the player and he will shortly be having his medical. If that goes satisfactorily, he will sign a three-month loan deal with an agreed deal at the end of that period.
"Brian brings goals. Every team needs extra fire power and you certainly need that in this division. If the source of goal dries up in one area, you need it from another.
"There has been a lot of responsibility on Gary Speed at both ends of the pitch but Brian has a goal in him, he will help us in that department."
He proved a vital asset to the Tykes team in the last campaign. He was voted Fans Player Of The Year many times.