The quartet join automatic qualifiers Tommy Fleetwood, Jon Rahm, Alex Noren and Thorbjorn Olese, Justin Rose, Francesco Molinari and Rory McIlroy in the Europe team.
Bjorn will be hoping those 12 men can regain the trophy from the United States at Le Golf National in Paris from September 28-30.
With five rookies in the eight automatic choices, Bjorn has stacked his captain’s picks with experience.
Garcia’s selection is perhaps the most contentious as his form has been poor this year, missing the cut at all four majors, but the Dane insists his contribution in the locker room will be just as important as on the golf course.
He said: “You’ve got to look at Sergio in certain ways. He is the heartbeat of the team, it like a football team going without a captain.
“Not only is he a fantastic golfer, but he also makes everyone around him better.
“He is what is great about the European team room, he is everything that European Ryder Cup is about.
“I watched him as a player and I watched him as a vice-captain and there is just something about him.”
Poulter’s selection is no surprise owing to his brilliant record in the competition, winning 12 of his 18 Ryder Cup matches while he also won on the PGA Tour earlier this year.
Bjorn added: “When he won in Houston, I thought he was on the track to be part of this team. The thing about Ian is when he gets confident and gets believing... I met him in the parking lot in Augusta he was like, ‘Right, I’m going to be there, I’m going to be part of your team’.
“That’s what he is all about, doing it on the big stage, he is a man for the occasion, he really is just a special person.
“The way he kept playing and kept talking that this was his only main focus, he was back in that frame of mind we like seeing.”
Casey makes his return to the European side for the first time in a decade, having regained his European Tour card last year in a bid to make the side.
Bjorn described his pick as a “no-brainer”, saying: “Paul’s commitment in what he was wanting to do, he has really shown that he has missed this part of his life and with a it really was a no-brainer for me to bring him back.
“He is world class, this is what he does, he brings world class golf to the team and he is a wonderful match player too, so it’s great to have him back.”
2016 Open winner Stenson made up the wild cards, despite suffering from injury recently.
“As soon as I knew what his focus was, it really wasn’t a big problem for me to pick him,” the captain said.
“The stature that he has, the person he is, the calmness he brings to the team room, he is very good at looking after the youngsters.
“He’s a very good guy to have around and he is a strong player.
“If I had written down 12 names before I started y captaincy it wouldn’t have been far away from this, I am very delighted with this team, I am proud to captain these 12 players. “