The Spaniard was sent off in the closing stages of West Ham United's 2-1 defeat to Leicester City in the first home game of the season when his high boot caught Jamie Vardy as he came up for a corner late on.
An appeal against the severity of the three-game ban – West Ham wanted it reduced to one game and argued it was not violent conduct and merely clumsy – was dismissed.
The club's desperation to appeal gave rise to suggestions that Bilic, like West Ham fans, were worried about understudy and summer signing Darren Randolph's ability to perform on the Premier League stage in Adrian's absence.
But while Randolph conceded four in a 4-3 defeat to Bournemouth in the very next game, he was not to blame for any of the goals and Hammers fans actually praised him for keeping them in the game at 2-0 down with a string of fine saves.
In his next game up at Anfield Randolph was part of a side that rewrote the history books.
In securing West Ham's first win at Liverpool's home ground in 52 years, the former Birmingham City 'keeper kept a clean sheet as Bilic's men ran out 3-0 victors.
And while West Ham's excellent defensive display meant he only had one shot to save in the 90 minutes, Randolph's organisation of the defence in front of him and his distribution were first class.
Adrian's return poses big question
He completes his spell as stand-in for Adrian against Newcastle United next time out.
But should he help the east Londoners end their home hoodoo – they have only won three times at Upton Park this year – should he be automatically replaced.
It is the kind of dilemma any good manager wants but it is a decision Bilic will have to think very carefully about.
Adrian: The making of a West Ham cult hero
Adrian is something of a cult hero to Hammers fans for his goalkeeping skills and the passion he brings to the number one shirt at the Boleyn Ground.
He cemented his place in West Ham folklore last season when he threw his gloves to the floor before stepping up to score the winning penalty in an epic FA Cup replay against Everton.
But should Bilic bring Adrian straight back in, it will surely send out the wrong message to his squad who will want to see that if they are playing well they will keep the shirt.
There is also the risk that Adrian will be somewhat rusty after his enforced five-week break and should he make a mistake Bilic's decision to throw him straight back in is open to criticism.
Others would argue that Randolph signed for the club in the summer fully aware of his place in the pecking order and may get another chance in cup matches.
With a trip to Leicester in the League Cup looming after the Newcastle game, perhaps the roles will be reversed and Randolph will keep his place for Premier League games while Adrian will be eased back in against the Foxes.