Martin Keown has admitted to BBC Sport that he was worried whether West Ham United players would take to David Moyes's intensive training-ground routine, after hearing about the Scot's methods, but acknowledges that he has transformed the team.
The Irons hammered Huddersfield Town 4-1 away from home on Saturday to move into the dizzy heights of 11th in the Premier League and five points clear of the drop zone.
It was the clearest example yet that West Ham are headed in the right direction under Moyes, who replaced Slaven Bilic at the start of November.
United have now only lost one of their last eight Premier League games - a 3-2 defeat by Newcastle - in a run that has included home games with Arsenal and Chelsea, and away to Tottenham.
Marko Arnautovic's improvement under Moyes compared to his form under Bilic is symbolic of the good work employed by the former Everton boss, with Arnautovic scoring again on Saturday to make it six goals in eight games.
And Keown admits that the London side are "unrecognisable" since the 54-year-old turned up.
"[West Ham are] unrecognisable. I am told he is really hands-on on the training ground", he told BBC Sport. "I was worried was he too intense. Would they respond well enough for him.
"Arnautovic, ask him how grateful he is for David Moyes coming into that football club."