Southampton midfielder James Ward-Prowse, Leicester striker Jamie Vardy, and Everton defender Seamus Coleman complete the six-strong shortlist for the latest monthly award.
Mane continued his fine February form into March, contributing three goals and one assist as Liverpool collected 10 points from their four Premier League games.
Robertson also played a part in all four of those fixtures, specifically delivering a pinpoint cross as the Reds opened the scoring in the crucial clash with Tottenham at Anfield.
The form of Bernardo Silva ensured that City have remained level pegging with Liverpool in the title race, with the Portuguese star scoring one and assisting the other in a 2-0 win over Fulham.
Ward-Prowse has been on fire since the turn of the calendar year, with many believing him unlucky not to receive an England call-up. He scored twice more for the Saints in March.
Vardy has played a big role in Leicester's recent turnaround under Brendan Rodgers. The former England forward scored four times in March, notably in wins over Fulham and Bournemouth.
Coleman helped a previously porous Everton keep three clean sheets in four Premier League games during the course of March, even bagging an assist in a 2-0 away win against West Ham.
The winner will be announced at the end of next week on Friday 12 April.