The winger, a summer signing from Walsall, has served a three-match ban following his red card in the 1-0 home defeat to MK Dons.
The Blades have lost their two Sky Bet League One encounters in his absence and Weir knows he was a big miss.
"That's great for us, we have really missed him," Weir said.
"He brings something different to the team. He brings pace and power and all of a sudden teams are defending five or 10 yards deeper. We know what he is capable of and it will make a big difference to have him back involved.
"Febian is different to most players in respect to his attributes so we have missed him. It's not an excuse for the games we have lost, but it is definitely a contributing factor."
The Blades, without a win since the opening day of the season, face a tough test if they are to kickstart their campaign as Simon Grayson's North End arrive in South Yorkshire unbeaten.
Although they have not won at Bramall Lane since 1978, Weir expects them to be confident of ending that hoodoo.
"They are very well organised, they are strong and physical," he added.
"They will be full of confidence and coming here expecting to win. We are not winning so it will obviously be difficult for us. They'll be confident so it's up to us to stop them."
- Sports & Recreation