Delph has been shortlisted along with Millwall pair Andy Frampton and Neil Harris and Leicester City's Matt Fryatt as the votes continue to pour in for January.
The teenager, who is the subject of interest from Premiership clubs, was on target in United's recent win over Brighton.
Voting for this month's award closes at midnight on January 31.
Fans can vote for their player of the month at: http://fansaward.givemefootball.com/vote?pid=2&cid=10207