His number one goalkeeper Adrian has on the whole been superb for the club since signing from Real Betis on a free transfer in 2013, quickly establishing himself as the main man.
But he does on rare occasions have the odd erratic or hot headed moment, the sending off against Leicester City in the first home game of the season after rushing up front for a corner being a case in point.
Question marks over number one
He was at fault for a goal against Crystal Palace recently and has struggled to make any notable saves of late as the Hammers defence has consistently leaked goals, without losing games.
Adrian is something of a cult hero in East London after his winning penalty heroics against Everton in last season's FA Cup.
Randolph on the rise
But such has been the brilliant form of Darren Randolph in cup games and during Adrian's suspension this season, it has put the Spaniard's performances under the microscope.
The Republic of Ireland goalkeeper was also a hero of his country's qualification for the European Championships in France this summer.
But Bilic stuck with his number one and was proved right as Adrian saved a crucial penalty from Troy Deeney at the death which would have made for a nervy final few moments at 3-2.
Bilic pokes fun
That came just days after he went the wrong way for Leonardo Ulloa's controversial last gasp penalty which handed Leicester City a 2-2 draw and dented West Ham's Champions League push at the King Power Stadium.
And speaking to the club's official website after the game, Bilic quipped it was about time his stopper started backing up his reputation.
"Well that (penalty save) was about time, because I heard a lot 'he is good' and I go 'where, yea?'," Bilic quipped on West Ham TV.
"I was like ‘Any chance?!’ So it was a good night for us."