Hagan to make first start for Rebels
Hagan's inclusion for the injured Laurie Weeks, who suffered a hamstring injury at training on Tuesday, at tighthead prop is the only change to the starting line up that defeated the Cheetahs 36-14 last weekend.
Hagan has made six appearances off the bench this season after he joined the Rebels in 2016.
Tim Metcher, named on the reserves bench, has been recalled into the team for the first time this season after two appearances last season.
"Laurie [Weeks] did a hamstring at the end of training on Tuesday so unfortunately he's out for a period of time and certainly won't play before the beginning of June," McGahan said.
"It's nice and easy for us, we bring in Jamie Hagan into the starting side, he's been gathering time off the bench and going really well so he's pretty excited to be an Irishman starting a Super Rugby game and Tim Metcher comes onto the bench."
Reece Hodge will remain at Outside Centre after scoring tries on either side of half-time against the Cheetahs last weekend - his second double of the season in five appearances.
Rebels flank Colby Fainga'a will start on the reserves bench for a second week after a successful return to Super Rugby against the Cheetahs following eight weeks on the sideline with an elbow injury suffered in the first round.
The Rebels, who take on the Blues for just the second time at Eden Park, are searching for their first win in Auckland following losses at North Harbour Stadium in Round 10, 2011 (23-40) and at Eden Park in Round 13, 2013 (32-36).
The two sides have split the four previous Super Rugby meetings with the home side winning on each occasion.
The Rebels equalled the franchise's record for most points in a game when they down the Blues 44-22 when the teams last met in a Super Rugby game at AAMI Park in Round 13, 2015.
Along with a maiden victory in Auckland, the Rebels are chasing a piece of franchise history with a fourth win on the road to set a new team record for away victories in a single season.
The Melbourne Rebels travel to New Zealand on Friday.
Melbourne Rebels: 15 Jonah Placid, 14 Sefa Naivalu, 13 Reece Hodge, 12 Tamati Ellison, 11 Cam Crawford , 10 Jack Debreczeni, 9 Nic Stirzaker (captain), 8 Adam Thomson, 7 Sean McMahon, 6 Jordy Reid, 5 Lopeti Timani, 4 Luke Jones, 3 Jamie Hagan, 2 James Hanson, 1 Toby Smith.
Replacements: 16 Pat Leafa, 17 Cruze Ah Nau, 18 Tim Metcher, 19 Sam Jeffries, 20 Colby Fainga'a, 21 Ben Meehan, 22 Kotaro Matsushima, 23 Sione Tuipulotu.
Date: Saturday, April 30
Venue: Eden Park, Auckland
Kick-off: 17.15 (15.15 AEST; 05.15 GMT)
Referee: Craig Joubert
Assistant referees: Glen Jackson, Brett Johnson
TMO: Ben Skeen