Ireland Under-20 scrum half Mark Dolan, a member of the Connacht Academy, retains his spot on the replacements bench and is joined by promising centre Eoin Grifin who is returning after a lay-off with a hamstring injury.
Connacht's starting line-up remains unchanged with Ronan Loughney and Jamie Hagan propping alongside Ireland international Sean Cronin.
With Michael Swift still out with a hand injury, Mike McCarthy is partnered by Bernie Upton in the second row and Andrew Browne, stand-in captain Johnny O'Connor and Ray Ofisa continue in the back row.
Frank Murphy and Ian Keatley will start again at half-back. Keatley has scored 195 points so far in this season's Magners League, leaving him second in the top points scorers' list behind the Ospreys' Dan Biggar.
Carr became Connacht's all-time top try scorer when he touched down twice against Edinburgh last time out. He overtook Conor McPhillips' longstanding record of 32 tries for the province.
As this is Connacht's last home game of the season, the Sportsground will throw open its doors for a 'Family Fun Day' with bouncy castles, face painting, giant board games, rugby-themed games and much more.
Family tickets for the event, which starts at 6pm, cost €50 for two adults and two children (Under-12) and include entry to the marquee where there will be music, food and a chance to mingle with the players before and after the game.
CONNACHT (v Cardiff Blues): Gavin Duffy; Brian Tuohy, Niva Ta'auso, Troy Nathan, Fionn Carr; Ian Keatley, Frank Murphy; Ronan Loughney, Sean Cronin, Jamie Hagan, Mike McCarthy, Bernie Upton, Andrew Browne, Johnny O'Connor (capt), Ray Ofisa.
Replacements: Adrian Flavin, Brett Wilkinson, Rodney Ah You, Mike McComish, John Muldoon, Mark Dolan, Keith Matthews, Eoin Griffin.