The Ghana international, who has not played since August, took a significant step on Saturday as he was included in the matchday squad for the Championship clash with Middlesbrough.
The 25-year-old was, however, an unused substitute.
“He trained last week and obviously was in the squad at the weekend,” Heckingbottom said, as reported by The Star.
“We rushed him through his rehab in terms of hitting all the markers and everything.
“He’s literally jumped from being shut down doing nothing for several weeks to going through a full rehab programme in about ten days. We wouldn’t let him train until he hit those markers.
“When he’s been out that length of time, you’ve got to do it properly, so we adhered to everything that the surgeon said.”
But it is even surprising that Yiadom is still on the books of Barnsley.
During the summer transfer window, the London-born was the subject of a transfer tussle between Premier League sides Huddersfield Town and Swansea City.
The Black Star was keen on moving up the ladder to play elite division football but a reported failed medical at Huddersfield meant he has had to return to the Tykes.
“He’s champing at the bit to get back playing. He’s been missing a long time,” Heckingbottom added.
“He’s fine, he’s fine in his own mind. He knows he’s okay.
“I have no qualms in picking him. I know he’s good enough - I can’t wait to have Yids back firing.”
Yiadom joined Barnsley from Barnet in summer last year.