Mooney scored the third goal of his loan spell from the Royals in the 3-2 defeat at deadly rivals Ipswich last weekend with a bullet header but is unavailable to face his parent club.
Manager Bryan Gunn may choose to hand youngster Cody McDonald a start alongside Alan Lee or push Alan Gow up front and bring in an extra midfielder.
Winger Lee Croft is struggling with a calf injury sustained at Portman Road while defender Dejan Stefanovic (knee), winger Wes Hoolahan (ankle) and striker Carl Cort (foot) are all sidelined for the rest of the season.
After Barnsley and Nottingham Forest both drew on Saturday the Canaries will not be relegated even if they lose but are still heading for their first season in the third tier since 1959/60.
Reading manager Steve Coppell expects to welcome back full-back Chris Armstrong for the trip to Carrow Road.
Armstrong missed the 2-0 win at Derby last Tuesday night with a knee problem which allowed on-loan Ipswich defender Dan Harding to make his debut but the former Sheffield United player should return on Monday night.
Top scorer Kevin Doyle has missed the last three games with a knee injury but is also in line to return but fellow striker Noel Hunt is out for the rest of the campaign.
Hunt suffered a fracture to his ankle after being stood on by Barnsley defender Darren Moore recently and he is unlikely to recover in time for any play-off matches.
Midfielder James Harper is a definite absentee as he recovers from a groin problem but Brynjar Gunnarsson (hamstring) and Graeme Murty (calf) both return to contention after successful comebacks in the reserves.
Ivar Ingimarsson remains a long-term absentee as he recovers from a knee operation.
Sporting Life