The Reds, set to confirm the signing of West Ham striker Elliott Lee today following the capture of Colchester midfielder George Moncur, say that they are under no pressure to sell their star trio.
Heckingbottom, who confirmed that first-team coach Tommy Wright will remain at the club, despite rumours he could link up again with Lee Johnson at Bristol City, said: “We have had interest (in the trio), we can’t lie and will probably get more.
“But Patrick (Cryne) has given me assurances and stressed that it is our team, they are our players and we are keeping them and the players are aware of this.
“And from my perspective, they are too valuable to let go. That’s how highly I rate them.
“At the minute, they are League One players if we sell them. If we sell them next summer or in January, we are a selling a Championship player and I believe in them 100 per cent as I know their value is only going to go up.”
Heckingbottom, who wants another four close-season signings to add to his first-team squad, admits that the club and Walsall are currently ‘miles apart’ regarding their valuation of Saddlers striker Tom Bradshaw, also interesting Rotherham United.
Barnsley have seen a bid of £350,000 rejected, while their interest has cooled in Plymouth centre-half Curtis Nelson.
Heckingbottom says he expects new Southampton manager Claude Puel to look at former loan winger Lloyd Isgrove before deciding on his future, with the Reds interested in re-signing him, while he admits that interest is growing in Ashley Fletcher, who he also wants to bring back to Oakwell.
Reds midfielder Otis Khan has joined Yeovil Town.
Rotherham United manager Alan Stubbs is confident that their recruitment drive will now speed up following the capture of Walsall winger Anthony Forde.
The 22-year-old has joined the Millers for an undisclosed fee, signing a three-year deal.
Stubbs, also linked with Millwall’s Lee Gregory, said: “Everyone is starting to come back for pre-season training. That means things will speed up as clubs will be in a position to make more firm decisions.”
Former Everton coach Andy Holden has been brought in as first-team coach.