Skipper Jose Maria Olazabal's wildcard choices see Ireland's Padraig Harrington miss out on the Ryder Cup team for the first time since 1997.
"Every one of you guessed Ian was going to be there. He has a great Ryder Cup record and he's playing well," Olazabal said while announcing his team to the world's media.
"He had some issues earlier this season when he got ill and couldn't play as much as he wanted. But his attitude and his spirit in the Ryder Cup has always been great and he is a player that likes to be in that environment.
"It gets the best out of him. At Valhalla in 2008 and at Celtic Manor in 2010 you didn't need to motivate him. Just by looking into his eyes you could tell he was going to give everything he had.
"Nicolas is going to be the only rookie in the team but his match play record is very good - he won the World Match Play Championship in Spain this year.
"He has had a very solid season and on top of that he has made the extra effort to try and get in the team - that showed me he wants to be a part of it.
"Nicolas has shown a lot of heart, a lot of character, and I think he has got the game and the desire to do well. It's also a long course at Medinah and he can take advantage of that, he will be suited to it."
Colsaerts was delighted to have been chosen.
"This has been something I've wanted since I was a little kid," said the 29-year-old. "I'm living proof that if you want something badly it's just a matter of time, if you put in the effort."
Poulter's selection always seemed inarguable. He narrowly missed out on automatic qualification and recently finished tied for third at the US PGA Championship, while he also has an outstanding Ryder Cup record, having won eight of his 11 matches and played key roles on the winning teams in 2004 and 2010. The Englishman was also the top scorer on either side in 2008, when Europe lost 16.5-11.5 - the last time the Cup was played on American soil.
Colsaerts, meanwhile, is a genuine wildcard: as well as being the only rookie player on the team, he becomes the first Belgian to play in the event.
Colsaerts's only serious rival for the final wildcard, Harrington, struggled in recent weeks and indeed most of the season with poor form.
He failed to qualify for this year's World Golf Championship tournaments, which are one rung down from the four Majors.
"I talked to the next few guys on the points list - David Lynn, Rafa Cabrera-Bello, Gonzalo Fernandez-Castano, Alvaro Quiros and Padraig," said Olazabal.
"I made those phone calls and it wasn't easy. They were disappointed not to make the team but they all took my decision well.
"Padraig played well at the US Masters, finishing eighth, he also had a good US Open (fourth) and a good Irish Open (seventh), but he is 19th on the points list and he was just a little bit too far down.
"I know he's a great player and I would have loved to have him in the team, in the same way I'd have loved to have Paul Casey, Robert Karlsson, Henrik Stenson - but you need to be playing well too."
Harrington also has a poor Ryder Cup record by the standards of his mostly stellar career, winning just nine of his 25 matches.
Olazabal believes the Europeans and the Americans, captained by Davis Love III, will be evenly matched at Medinah.
"Both teams are strong and I don't see that there is a favourite," he said. "But the support of the home crowd will be massive to the US.
"They will also set up the course the way they want and we are going to have to play really well to have a chance to win.
"The atmosphere will be electrifying so I need to prepare my players for that and make sure they don't allow themselves to be bothered by it.
"Luckily the guys have the experience to make that easier. We are playing great opponents - but anything can happen."
The Ryder Cup will be held from Friday September 28 to Sunday September 30 at the Illinois venue. Europe won the last edition at Celtic Manor 14.5-13.5.
European Ryder Cup team:
Ian Poulter (wildcard)
Nicolas Colsaerts (wildcard)