Captain Bailey has missed the last two games after sustaining an ankle problem in training, while striker Burton is battling against a knee problem.
Parkinson suggested Bailey has a better chance of returning, but may still opt to rest both players in order to get them back fully fit after Easter.
He told the club's official website: "Nick and Deon were missing (against MK Dons) and if you go into any game without your two top scorers, you are going to be slightly handicapped.
"They are good players but hopefully we can use this period as a rest period for them and they can come back fit to push us on in the last part of the season."
Goalkeeper Rob Elliot (groin) is still out so Darren Randolph keeps the gloves, while Kelly Youga (knee), Grant Basey (ankle) and Leon McKenzie (thigh) continue to struggle.