The Irishman made the claim after handing his wildcards to Sergio Garcia, Shane Lowry and Ian Poulter, overlooking Justin Rose despite his impressive record in the event and also a strong finish in the final qualifying event.
Garcia will be making his 10th appearance against the Americans, playing on six winning teams and becoming Europe’s record points-scorer with 25.5 points after the 2019 victory in Paris.
Poulter, who was also on that team, will be teeing up for a seventh time in the biennial event, having been on five winning sides and earning a pick the same number of times.
For Lowry, who slipped out of an automatic spot after the BMW PGA Championship at Wentworth, it will be a debut appearance in the event at Whistling Straits.
The trio will join automatic qualifiers Jon Rahm, Tommy Fleetwood, Tyrrell Hatton, Bernd Wiesberger, Rory McIlroy, Viktor Hovland, Paul Casey, Matthew Fitzpatrick and Lee Westwood in defending the trophy in Wisconsin. Hovland and Wiesberger will also be first-timers.
“It is a great team,” said Harrington. “It is the best ball-strikers’ team Europe has sent out in the Ryder Cup. We are playing a very strong golf course and I know they are good enough.”
The three-time major winner said he’d picked Garcia for his “passion” and said Poulter would “bring heart to the team”.
As for Lowry, he said that had been an “easy decision based on form” and that he “didn’t think of him as a rookie” through being both a major and WGC winner.
Rose, who was Europe’s star man in the 2014 win at Gleneagles, missed out despite picking up 13 points out of 23 in the event and also signing off with a bogey-free 65 to finish joint-sixth behind American Billy Horschel at Wentworth.
“I’d love to have Justin Rose in the team, but that’s not how it works,” said Harrington, who admitted that another former Scottish Open winner, Alex Noren, had also been unfortunate to miss out after a strong finish to the qualifying campaign.
“Ian and Sergio are the heart of the Ryder Cup team so I had to go with them, and Shane has been playing great golf all year, so Justin had to play his way in. As good as he is, there was just no place for him.
“JR did deliver this week, he performed. He came here under pressure, maybe a couple more weeks...it was just a step too far.
“I had a chat with him and absolute gentleman. He was clearly disappointed, after finishing with the eagle at the last, the glory of it all.”
Poulter, who had partnered Rose in past matches, added: “I feel for Justin. We all know what a class golfer he is. I haven’t spoken to him yet, but I know he will be disappointed. It’s a hard call to take from the captain.
“I’ve been in that situation myself a couple of times and the last thing you want is to be on the outside looking in. Rosey will get over it, though. He will be wishing us all the best, I am sure of that.”
Speaking before the picks were announced, Rose seemed to think he’d done enough to secure one of the spots.
“My record is as good as anybody's in that team,” he said, adding that it would be “disappointing” if he missed out.
“You reflect on why,” he remarked. “Is there something bigger at play because on the surface I feel pretty confident.
“I feel like I am on a path of moving forward again. I am not going to let it derail me for sure. It will be a blow of course. But it will give me an unwanted couple of weeks to recuperate.”