McIlroy, described by captain Darren Clarke as his on-course team leader, and Belgian Pieters won all three matches they played together and the Northern Irishman is unwilling to change his new companion when they get to France.
"I've got a partner beside me for the next 20 years, I'm not letting anyone else have him," the world number three told reporters as he put his arm around the Ryder Cup debutant following the 17-11 defeat by the United States on Sunday.
The 24-year-old Pieters, who triumphed 3 and 2 in his last-day singles against JB Holmes and lost in the company of Englishman Lee Westwood in Friday's opening foursomes, was Europe's leading scorer with four points from five matches.
That set a record for a European rookie, surpassing the three and a half points claimed by Englishman Paul Way in 1983 and by Spaniard Sergio Garcia and Scot Paul Lawrie in 1999.
"There are plenty of positives to take into Paris in two years' time," said McIlroy who lost a titanic battle with U.S. talisman Patrick Reed in the singles as the Americans ended a run of three straight defeats in the biennial team event.
"Some of the new blood we have, they have gotten over their first Ryder Cup and now they know what it's about and they know what they are going to expect next time," the 27-year-old added.
"We have...a group that have gotten much closer over the past seven days, a group that you could possibly all see again in two years' time," said McIlroy.
"It is disappointing to lose. I wish we could have that feeling we had at Gleneagles two years ago but it will make it that much better when we have that feeling again in Paris."
Clarke will not be captain when the competition is played at Le Golf National in 2018 but he is hopeful there will be some French representation.
"Whoever makes that team, it will be very strong again for the European Tour," Clarke said.
"As Rory rightly says, it could be exactly the same guys lining up again but if there is a French national, that would be wonderful as well."
(Editing by Ed Osmond)
