The centre-back was sold to Saudi Arabian side Al Ittihad on Sunday – just days after the head coach told a press conference he would not be leaving.
Hegazi had started just 15 matches under Bilic and on £70,000 a week was the club’s highest earner.
Albion felt the deal on the table was too good to turn down, with the move saving them around £7million in wages whilst also earning them a transfer fee in the region of £3million.
And while Hegazi was not desperate to leave Albion, he was open to a lucrative move to Saudi Arabia.
Yet Bilic told the club he wanted the Egyptian to stay.
The boss had also planned to have Hegazi in his starting XI for Monday’s trip to Brighton – with the boss then having to replace him with Semi Ajayi.
Speaking after the game at the Amex Stadium, Bilic went on record to say how disappointed he was with Hegazi’s departure.
He also refused to publicly assure fans he would stay at the club – with reports emerging earlier in the day that he was considering his future at The Hawthorns.
But while there is tension between the head coach and the club’s hierarchy, the Express & Star understands Bilic is unlikely to quit as Albion’s boss and is focusing all his efforts on keeping the club in the Premier League.
Meanwhile, Albion are still waiting to find out if Kamil Grosicki can join Forest on loan.
Chris Hughton’s side swooped to sign the Poland international on transfer deadline day with Grosicki agreeing terms on a temporary switch that could lead to a permanent transfer.
But it is understood the paperwork for the deal was submitted 21 seconds after the 5pm deadline.
A decision on whether the move can go through is now expected tomorrow, after an aribitration hearing heard details of the case yesterday.
“As manager, I’m very much hoping it’s going to be soon,” Hughton said when asked yesterday if there had been any update on Grosicki.
“I can only pass on the information I’ve been given, and that is that it’s still very much in the hands of the club and the Football League.
“But let’s hope there’s a decision as soon as possible.
“It’s something we all want to happen, and happen as quickly as possible. Let’s hope it’s soon.”
The Express & Star understands that if the 32-year-old doesn’t get the green light to move to the City Ground, Albion expect to be able to add him to their Premier League squad.
All clubs had to submit their 25-man squads to the Premier League last Tuesday.
But Albion submitted 24 names – leaving space for Grosicki to be registered if he returns.