The goalkeeper was recalled from an impressive loan spell with Northampton after Bradford first-choice Jon McLaughlin was sent off in the infamous recent game against Crawley that ended with an on-pitch brawl.
McLaughlin's three-game ban is now over but he may not be able to dislodge Duke from the starting line-up.
"We are fortunate to have two very good goalkeepers at the football club at this moment," Bantams boss Phil Parkinson told his club's official website.
Check out Duke's career record by clicking the link below.
Aidy Boothroyd meanwhile has called on his side to garner as many points as possible between now and the end of the season and give Cobblers fans plenty to shout out about going into the summer.
"We want to finish strongly," he told the official club website.