The Croatian boss is under serious pressure, but Hartson does not want Bilic to go.
The former West Ham striker said: “There’s a bit of ill feeling around the club. I think the problem Bilic and West Ham have got is that they overachieved last season. They are under pressure.
“Would I be surprised if West Ham decided to change it? No. Would I be disappointed? Yes, of course. But it’s a result business.”
Bilic was heavily criticised when West Ham lost against Tottenham Hotspur last weekend.
The Hammers were 2-1 up heading into the final stages of the match, but Bilic decided to take a defensive approach and it backfired.
West Ham threw away their advantage, and ended up collapsing to a defeat at White Hart Lane.
Bilic’s men are now just one point above the relegation zone, and their upcoming fixtures appear to be very tough.
West Ham take on Manchester United, Arsenal and Liverpool in the coming weeks - with the pressure on them to make sure that they can pull off an upset.