24-year old Welsh midfielder Collison has not played this season because of a knee injury sustained in May whilst 31-year old Frenchman Diarra has made just one appearance for the Hammers since joining from Marseille in the summer due to various problems.
However, Allardyce is confident that duo will soon be back in action for the East Londoners which will ease the pain of losing key midfielder Mohamed Diame for a few weeks after he suffered a hamstring injury in the weekend's 3-2 loss to Liverpool.
"Alou Diarra [is close], but he hasn't played a Premier League game yet, so he hasn't felt what it is like to play there and that would be difficult for him after a three-month lay-off," Allardyce told talkSPORT.
"Jack Collison might be close in the next couple of weeks to actually start joining in but he hasn't kicked a ball since the play-off final last year.
"At least to have the bodies back and bring them on from the subs bench is going to be important to us."