Winger Routledge has returned to Loftus Road on loan from Newcastle while full-back Chimbonda has joined on a free after leaving Blackburn.
Boss Neil Warnock has also signed West Brom striker Ishmael Miller on loan but he has a slight hamstring injury.
Heidar Helguson is fit after a thigh problem and pushing to replace Rob Hulse, who has failed to score in his last seven outings, in attack.
Midfielder Akos Buzsaky is still out with a knee injury but has been pencilled in for a return next month.
Defender Peter Ramage (cruciate) and broken-leg victims Jamie Mackie and Patrick Agyemang are the long-term absentees.
Source: PA
Source: PA