GLENEAGLES, September 26, 2014 (AFP) - Masters runner-up Spieth and Reed beat Ian Poulter and Stephen Gallacher 5 and 4 in morning fourballs but did not see action in afternoon foursomes, where Americans managed only a half-point to trail Europe 5-3 after day one of the biennial golf showdown at Gleneagles.
Spieth said he thought an early win would be enough to book an afternoon return based on what Watson had said before, but that wasn't what happened.
"I take the blame," Watson said. "I assessed that even though they won in the morning, there maybe was a better team the fourball in the afternoon.
"That decision not to play them was a hard decision to make. I had some doubt in making that decision, but my gut feeling said it was the right decision.
"You can't play everybody. You're going to be second guessed and obviously you're going to second guess me on that decision right there."
Watson was disappointed in Bubba Watson and Webb Simpson losing 5 and 4 in fourballs to Justin Rose and Henrik Stenson and benched that duo as well.
"Thought I would probably play Bubba twice, but it didn't work out that way," Watson said. "You had some horses that you looked at, you were going to ride. When they don't perform, you have to make a decision not to play them and that's what I did."
Watson rode Phil Mickelson and Keegan Bradley for two matches after they won 1-up over Rory McIlroy and Sergio Garcia but they looked tired late in losing 3 and 2 to Graeme McDowell and Victor Dubuisson, who didn't play early.
"Keegan and Phil, I had to give them a shot there," Watson said. "They have done well in (foursomes) and I had to give them a go."
Asked if he had been outcoached by European rival Paul McGinley, Watson replied, "We were outplayed, I know that."
Watson created two new pairings for Saturday's morning fourballs, sending out Watson with Matt Kuchar, a foursomes loser alongside Jim Furyk, who will now partner Hunter Mahan, a foursomes loser alongside Zach Johnson.
Spieth and Reed will return against Martin Kaymer and Thomas Bjorn while young stars Rickie Fowler and Rory McIlroy will be matched up, the world number one with England's Ian Poulter and Fowler with rookie Jimmy Walker, who halved twice Friday.
"We're 5-3 but we have really strong morning pairings," Watson said. "Bubba is going back out and he's one of our studs. I really like what I see.
"Yeah, we're behind right now. We were up in the morning. This is ebbs and flows. Right now, we're in an ebb."
But Watson has confidence his side is far from finished.
"Even though they are disappointed, there was the attitude, 'All right, let's go get this thing done,'" said Watson. "I'm disappointed with the results but I'm not disappointed with the attitude of the team.
"These guys are all great players. They can get it done. I believe in them and they believe in themselves. You didn't get it done today, but the game is still on.
"It's not a sprint. It's a marathon."