Mickelson clinched his fifth Major title by three shots, closing with a stunning five-under-par 66 at Muirfield, while compatriots Hunter Mahan (joint ninth) and Brandt Snedeker (tied for 11th) also fared well after contending for much of the week.
All three Americans are riding high in the points standings for automatic Presidents Cup selection, along with former Major winners Tiger Woods, Keegan Bradley, Webb Simpson and Zach Johnson.
"Phil Mickelson, who has played in all nine Presidents Cups to date, won the Open Championship with one of the best rounds of golf you'll ever see," an admiring Couples wrote in his official captain's blog.
"Several players I expect to be on the US Cup team this fall also impressed me with their play at Muirfield, namely Hunter Mahan and Brandt Snedeker. Both players have yet to win a Major, but they continue to contend in these big events."
Mahan has recorded four top-10s in 19 starts on the 2013 PGA Tour, including a tie for fourth at the US Open and a share of ninth at Muirfield.
Snedeker, widely regarded as one of the best putters in the game, won his fifth US PGA Tour title at the Pebble Beach National Pro-Am in February before tying for sixth at the Masters two month later.
He has piled up seven top-10 finishes in 15 appearances on the circuit this season.
"We're just over two months away from the Presidents Cup and the automatic qualification process is winding down," Couples said of the Ryder Cup-style event which will be played at Muirfield Village Golf Club in Dublin, Ohio from October 3-6.
"Looking at the current top 10 in the US team standings, even our young players have significant Ryder Cup and/or Presidents Cup experience, which is always a plus."
The leading 10 players in the US points standings after the Deutsche Bank Championship ends on September 2 will automatically qualify for the Presidents Cup.
Going into this week's Canadian Open, the top 10 are: Woods (1), Mickelson (2), Matt Kuchar (3), Snedeker (4), Bill Haas (5), Mahan (6), Bradley (7), Simpson (8), Steve Stricker (9) and Johnson (10).
On the bubble, and perhaps relying on one of two captain's picks, are: Bubba Watson (11), Dustin Johnson (12), Billy Horschel (13), Jason Dufner (14) and Kevin Streelman (15).
The Presidents Cup is a biennial competition which pits a 12-man team from the United States against a line-up of international players from outside Europe.
The US have established a virtual stranglehold over the opponents, winning the trophy at Royal Melbourne Golf Club in Australia in 2011 for the seventh time in nine editions.
The only success for the Internationals came in 1998 when the event was first staged in Melbourne. In 2003, the teams battled to a 17-17 draw in South Africa.
- Sports & Recreation
- Brandt Snedeker
- Hunter Mahan
- Presidents Cup
- Tiger Woods
- Keegan Bradley
- Webb Simpson