It is timely boost for R's boss Ian Holloway who has likely to lose injury victim Arthur Gnohere for another eight weeks after injuring his knee in the reserve's fixture on Tuesday.
Ollie has also had to deal with injuries to key players Martin Rowlands, Tony Thorpe, Richard Edghill and Nick Culkin- all a minimum of a few weeks away from full fitness.
So, Bircham's return is well timed. Despite missing last week's win against league-leaders Wigan he has completed his one game ban and shall return alongside captain Kevin Gallen in centre-midfield.
Jamie Cureton is to continue alongside Paul Furlong up front despite missing training earlier this week and Gareth Ainsworth will keep his place on the right-wing.
Georges Santos is the only new doubt ahead of Saturday's fixture.
The Frenchman suffered a recurrence of his Achilles injury and did not train yesterday.
However the R's medical team are optimistic he will recover in time to take his place in the starting eleven.
Frankie Simek is on standby should Santos miss out.