And he wants them to feel free to express themselves.
The 22-year-old Yachvili from Biarritz has only one cap while goalkicker Gelez, aged 24, has played for Les Bleus seven times.
Yachvili replaces captain Fabien Galthie, who ruled himself out last week with a shoulder injury, while Gelez has been retained after a near faultless kicking performance in France's 38-3 win over Scotland on February 23.
"It is true to say that they are young and that they lack experience but they have a lot of enthusiasm," Laporte said.
"They will gain that experience by playing more games. At the moment they definitely are the best at those positions.
"What we are expecting from them is to be themselves and to feel free to express their rugby.
"We don't know yet whether they will be selected again for Italy - it will all depend on their performance on Saturday as well as on the evolution of injuries.
"But it would not be a bad thing for us to rely on the same half-pack partnership for the rest of the tournament."
In the absence of the charismatic Galthie, back row forward Fabien Pelous will lead the defending 6 Nations champions.
France team to play Ireland in Dublin on Saturday, March 8:
C Poitrenaud, A Rougerie, X Garbajosa, D Traille, V Clerc, F Gelez, D Yachvili, I Harinordoquy, O Magne, S Betsen, O Brouzet, F Pelous (capt), S Marconnet, R Ibanez, JJ Crenca.
Replacements: J-B Rue, C Califano, D Auradou, S Chabal, M Barrau, G Merceron, T Castaignede.