GLENEAGLES, Scotland, Aug 27, 2012 (AFP) - Poulter, 32, will be competing in his fourth Ryder Cup since making his debut at Oakland Hills in 2004 while the 29-year-old Colsaerts will be the only debutant in Olazabal's team.
It is Poulter's second wildcard after he received a similar pick in 2008, while Colsaerts is the first Belgian in the 85-year history of the event to compete in the Ryder Cup.
"Ian's had a great Ryder Cup record," said Olazabal. "He was playing well, he had some issues early in the season.
"He got ill and he couldn't play as much as he could, but his attitude and his spirit in the Ryder Cup team has always been great. He's one of those players that likes to be in that situation.
"I think he gets the best out of him playing the Ryder Cup. The two times I had the opportunity to share a few moments with him at Valhalla and Celtic Manor, you didn't need to motivate him."
Olazabal singled out Colsaerts for his determination and effort after the Belgian had finished two places outside of automatically qualifying for the European team.
But after sharing seventh in this month's PGA Tour Wyndham Championship and then making the effort to return to Europe for last week's Johnnie Walker Championship, where he shared 19th place, Olazabal afforded him a pick.
"Nicolas, obviously he's a rookie. If you look at the team, he's going to be the only rookie on the team," the Spaniard said.
"We do have an experienced team. His match play record is very good. He finished runner-up last year at the World Match Play. He won this year at the World Match Play.
"He's had a very solid season, and on top of that, he's made the extra effort trying to make the team. He really showed me that he wants to be a part of that team. Those are the reasons for me to pick him."
Olazabal indicated he had also phoned all those immediately behind Colsaerts on the qualifying table including the 19th-placed Padraig Harrington of Ireland.
Harrington's non-selection ends a run of six straight Ryder Cup caps for the triple Major-winning Irishman.
"Well, I talked to Padraig last night, and I was very straight to the point," said Olazabal.
"I know he tried hard. He played well at the Masters; he finished eighth. He had a good US Open and then the following week he had a great Irish Open. But you know, he was 19th on the list. He was just a little bit down the list.
"I know he's a great player. I would have loved to have him on the team the same way I would have loved to have Paul Casey, Robert Karlsson, Henrik Stenson. Those are great players.
"But you need to be playing good, simple as that. I think he took it well, and that was it."
US captain Davis Love will announce his four wildcard picks on September 4 in New York.
European team for Ryder Cup
Rory McIlroy (NIR), Justin Rose (ENG), Paul Lawrie (SCO), Graeme McDowell (NIR), Francesco Molinari (ITA), Luke Donald (ENG), Lee Westwood (ENG), Sergio Garcia (ESP), Peter Hanson (SWE), Martin Kaymer (GER), Ian Poulter (ENG), Nicolas Colsaerts (BEL)