Conan set for Ireland bow
Conan, 23, will hope to earn a place in head coach Joe Schmidt's final 31-man squad for the tournament, which will be announced on August 31.
Schmidt said that Rob Herring, Noel Reid and Kieran Marmion were not definitively out of his plans for the World Cup, despite having been released from the squad to return to club duty this week.
"Technically they're not here, but they haven't left the squad. I'm still in contact with them," he told a press conference.
"I know that Noel is preparing to play next weekend, against Rob Herring in the Leinster-Ulster clash. And Kieran Marmion is down to play off the bench against Castres this weekend, and again it's because we need players to be match-fit.
"If we can't provide all the games for them, then next Friday and Saturday gives us a really good window."
Conan's Leinster teammate Sean O'Brien will captain the team for the first time at number eight, with regular captain Paul O'Connell starting from the bench.
Ian Madigan has been handed an opportunity to shine at No.10, while wing Simon Zebo will be tested at fullback.
Scrumhalf Isaac Boss, prop Dave Kilcoyne, lock Dan Tuohy and Conan are the other fringe players included in the starting XV.
Tighthead prop Mike Ross is the only player to retain his place from last weekend's 35-21 victory over Wales in Cardiff.
After tackling the Scots, Ireland face a return game against Wales in Dublin on August 29 before taking on World Cup hosts England at Twickenham on September 5.
Schmidt's men begin the World Cup against Canada in Cardiff on September 19 and will also face Romania, Italy and France in Pool D.
Ireland: 15 Simon Zebo, 14 Tommy Bowe, 13 Jared Payne, 12 Gordon D'Arcy, 11 Luke Fitzgerald, 10 Ian Madigan, 9 Isaac Boss, 8 Sean O'Brien (captain), 7 Chris Henry, 6 Jack Conan, 5 Dan Tuohy, 4 Devin Toner, 3 Mike Ross, 2 Sean Cronin, 1 Dave Kilcoyne.
Replacements: 16 Richardt Strauss, 17 Michael Bent, 18 Nathan White, 19 Paul O'Connell, 20 Jordi Murphy, 21 Eoin Reddan, 22 Paddy Jackson, 23 Dave Kearney.
Date: Saturday, August 15
Venue: Aviva Stadium, Dublin
Kick-off: 17.00 (16.00 GMT)
Referee: Pascal Gauzère (France)
Assistant referees: Jérôme Garcès (France), Marius Mitrea (Italy)
TMO: Graham Hughes (England)
Agence France-Presse
