All season long it has been clear the Blades' top scorer was the player they could least cope with out, especially once fellow strikers Rhian Brewster and David McGoldrick had their campaigns ended by injury and Lys Mousset was loaned out in January.
Since Sharp injured his hamstring against Barnsley in the final match before the international break, his team have picked up five points from a possible 15 and scored three goals.
Oli McBurnie's injury meant they started without a recognised centre-forward in Monday's 1-1 draw at Bristol City, No 10s Morgan Gibbs-White and Illian Ndiaye pushed further up the field and 18-year-old Danish specialist Will Osula coming off the bench for only the third time, having been preferred to fellow teenager Daniel Jebbison in the squad.
Quite simply, no other Blades striker can finish anything like as well as Sharp. Brewster, McGoldrick and Mousset have eight league goals between them to Sharp's 14 this season. McBurnie, Jebbison and Osula have none.
But the hope is that Sharp could be back to face Cardiff City on Saturday.
"I'm hoping to have Billy," said manager Heckingbottom. "Everything has to go to plan for that, he needs to have the perfect week in terms of hitting all his markers, but I know he has had a good day today (Monday). We need to make sure he's fit and available and ready to help us because we want him back.
"Oli has got damage, his foot is huge. He was nowhere near making the game. It has shown some damage to a bone and to a ligament, so we need to get to the extent of that."
Heckingbottom was also worried when George Baldock had to come off with a muscle injury. Injury ended his deputy Jayden Bogle's season in February, so the incredibly versatile Ben Osborn replaced Baldock at Ashton Gate.
"Yeah it is (a concern) just because of the fact that we had to bring him off, it is the same leg," said Heckingbottom. "Hopefully, it's a warning but if you are bringing anyone off with a muscle injury you are always concerned."
The Blades ended the Easter programme in the Championship's final play-off spot. They have three games left to book their place.