Bradley and Phil Mickelson won all three of their fourballs or foursome matches in Chicago, while Simpson came together with Bubba Watson for two 5&4 victories and one defeat - on the final hole.
Watson has admitted that he has had these pairings in mind when handing out his three wildcards and hinted that he would look to utilise the "great chemistry" of the quartet on Friday and Saturday of this week.
"A part of me, when I chose the captain's picks, was about chemistry," he told reporters. "Obviously Webb Simpson and Bubba Watson have good chemistry. Also Keegan Bradley and Phil Mickelson have good chemistry that they've shown in the past.
"You have to go back on past experiences. Also the way they're playing is a big factor as well. There's no one factor, it's a combination of factors."