Europe retained the Ryder Cup and condemned America to their eighth defeat in the last 10 with a 16.5-11.5 victory at Gleneagles.
After a disappointing weekend for the American team, Mickelson's comments in the news conference will raise questions over the credentials of Tom Watson's captaincy.
The 44-year-old openly praised 2008 winning Ryder Cup captain Paul Azinger and the effect he had on the team, with Watson sitting nearby.
Azinger was the last captain to lead the Americans to victory over Europe so it will be an interesting decision to see who is elected for the 2016 competition at the Hazeltine National Golf Course.
Captain Watson was quick to defend Mickelson's comments, stating to reporters: "He has a difference of opinion. That's OK. My management philosophy is different than his."
But it raises doubts as to whether Watson was the right man for the job, with these comments coming from a five-time major winner and more senior members of the American team.
Former Europe captain, Nick Faldo was critical of Mickelson's comments claiming he had "thrown his captain right under the bus".
Mickelson was making a record 10th Ryder Cup appearance and was said to be unhappy at being left out by Watson on Saturday.
And the American who won two out of three points, said Watson had "strayed from a winning formula."
"There were two things that allowed us to play our best that Paul Azinger did," said Mickelson, a five-time major winner.
"First, he got everybody invested in the process. He got everybody invested in who they were going to play with, who the picks were going to be, who was going to be in their 'pod', when they would play, and they had a great leader for each pod. We hung out together.
"The other thing that Paul did really well was he had a great game-plan for us - how we were going to go about doing this, how we were going to go about playing together, if so-and-so is playing well, if so-and-so is not playing well.
"Unfortunately we have strayed from a winning formula for the last three Ryder Cups and we need to consider maybe getting back to that formula that helped us play our best."
After the Europeans convincing win, many people are calling for a change in how the American team is made up.
Before 1979, The Ryder Cup was played between America and Great Britain & Ireland but due to America's dominance, it was expanded to Europe as a whole.
Could it possibly be time to do the same with the American team after their eighth loss in 10? There is talk of other British colonies joining the Americans, with the likes of Australia, Canada and South Africa getting involved.
This would allow Adam Scott (world number 2) Jason Day (world number 8) and Charles Schwartzel (previous Masters winner) the opportunity to strengthen the American team.
Whatever happens, The 2016 Ryder Cup promises to be as entertaining and dramatic as ever before.