Fitzgerald has not played for the province since January
Leinster head coach has named his team for Saturday's game against Connacht in The Sportsground.
For the trip to Galway, Cullen is able to call upon 12 players who were involved in the match day and extended match day squad with Ireland last weekend against Scotland in the 6 Nations. He is also able to call upon the fit again Luke Fitzgerald who returns for this first time since January to make his 150th appearance for the province.
With Fergus McFadden coming on to the right wing, captain Isa Nacewa who makes his 100th Pro12 appearance on Saturday reverts to full back with Fitzgerald taking up the number 11 jersey. Ben Te'o and Garry Ringrose continue in midfield.
Luke McGrath again starts at scrumhalf with Ian Madigan joining him in the half backs.
Cian Healy comes in at loose head prop with Richardt Strauss also starting at hooker. Tadhg Furlong completes the front row.
Behind them Ross Molony and Hayden Triggs start in the second row, while in the back row Dominic Ryan starts from blind side with Josh van der Flier and Rhys Ruddock back from Ireland duty to complete the pack.
Irish players Sean Cronin, Jack McGrath, Mike Ross, Devin Toner, Jamie Heaslip and Eoin Reddan are all included on the bench.
Leinster team and replacements to face Connacht:
(15-9): Isa Nacewa (capt), Fergus McFadden, Garry Ringrose, Ben Te'o, Luke Fitzgerald, Ian Madigan, Luke McGrath.
(1-8): Cian Healy, Richardt Strauss, Tadhg Furlong, Ross Molony, Hayden Triggs, Dominic Ryan, Josh van der Flier, Rhys Ruddock.
Replacements (16-23): Sean Cronin, Jack McGrath, Mike Ross, Devin Toner, Jamie Heaslip, Eoin Reddan, Noel Reid, Zane Kirchner.