Joint overnight leader Ross Fisher (71) shares second with Thailand's Thongchai Jaidee and Francesco Molinari of Italy.
The Swede, along with Miguel-Angel Jimenez and Edoardo and Francesco Molinari, have been left out of the opening day's fourball action.
BBC: Ryder Cup 2010: Westwood aims to lead Europe by example
Italian brothers Edoardo and Francesco Molinari formed another pair, while world number four Lee Westwood teamed up with USPGA champion Martin Kaymer.
Denmark's Thomas Bjorn was another shot back in fourth on nine under overall, while Australia's Adam Scott and Italian Francesco Molinari tied for fifth.
Garcia fared better and remained in contention after a battling 71 for one-under 143, but trails halfway leader Francesco Molinari of Italy by five shots.
But in joint fifth, he still trails leader Francesco Molinari of Italy by three shots going into the final round at the links course in Inverness.
McDowell is two under and in a share of 30th - 10 behind Ian Poulter who is two ahead of Ross Fisher, Francesco Molinari and Thongchai Jaidee.
That chasing trio ended the day tied for second on 10-under 206, two shots clear of three-time major winner Harrington (67) and Ryder Cup winner Francesco Molinari (68).
The European team also included Lee Westwood, Rory McIlroy, Martin Kaymer, Ian Poulter, Ross Fisher, Francesco Molinari, Edoardo Molinari, Peter Hanson, Luke Donald, Padraig Harrington and Miguel Angel Jimenez.
South Africa's 2010 British Open champion Louis Oosthuizen made 67 to be tied for seventh on 139 along with Italy's Francesco Molinari (68), Irishman Shane Lowry (70) and Spain's Pablo Larrazabal (68).
Meanwhile, another player who made his Ryder Cup debut two years ago, Francesco Molinari, boosted his chance of a second appearance in September by winning the European Tour's Spanish Open on Sunday.
England's Ian Poulter, who finished seventh at the Masters earlier this month, made the cut by a single shot, while Francesco Molinari -- part of Europe's successful Ryder Cup team in 2010 -- is on seven-under.
Colsaerts and Poulter join world No. 1 Rory McIlroy, Justin Rose, Johnnie Walker winner Paul Lawrie, McDowell, Francesco Molinari, Luke Donald, Lee Westwood, Sergio Garcia, Peter Hanson and Kaymer in the team for the September 28-30 event.
In the pro-am format, Montgomerie is playing with his brother Douglas and Ryder Cup hero Graeme McDowell, while Italian brothers Edoardo and Francesco Molinari play in the same fourball alongside amateur partner Gianfranco Zola, the former West Ham manager and Chelsea striker.
But Ryder Cup brothers Francesco and Edoardo Molinari were among those who failed to make it through to the final day at St Andrews, along with Swede Peter Hanson.
For Europe, Graeme McDowell and Rory McIlroy played with Luke Donald and Martin Kaymer, Harrington and Peter Hanson went out with Lee Westwood and Ross Fisher with Edoardo Molinari and his brother Francesco taking on Ian Poulter and Miguel Angel Jimenez.
But the laugh on the last was left to the Molinari brothers who held their nerve to secure a half point from the jaws of defeat as Francesco cleared the water feature protecting the green to land the ball within inches of the hole.
应用推荐