The six of them have combined for 29 Ryder Cup appearances.
Ireland's McDowell, 38, was on his sofa when the last match was played and says Europe are confident of reclaiming the Cup despite the Americans holding all four majors and having the world's top-ranked player in Justin Thomas.
"All five are widely respected throughout the game, are all current players who are well known to the players who will be in our team come September and they also all possess a knowledge and understanding of what to expect from the golf course at Le Golf National too", he said at Wentworth, ahead of this week's PGA Championship.
"We know each other really well, especially in the context of being part of the intense pressures of the backroom team in Ryder Cup week", Harrington said. "I was keen to see that kind of angle to it and, like I said, when Thomas asked me, I jumped at the chance". McDowell, who claimed the winning point for Europe at Celtic Manor in 2010, and Donald will be making their vice-captain debuts. "They have forthright opinions which is vital under the spotlight of a Ryder Cup week and can only help our cause as we try and regain the trophy". "We know they are going to field a very strong team and be very confident but I think we've proved ourselves over the last 20 years or so that we can compete at that team level in a Ryder Cup".
Westwood is a seven-time victor as a player in the contest against the US.
GETTYEurope captain Thomas Bjorn with his Ryder Cup back room team
'The fact I won't be able to play for another month means that making the team would be a long shot, so that helped, ' conceded Donald.
USA captain Jim Furyk has Tiger Woods, Steve Stricker and Davis Love III as assistants.
Europe will seek to regain the trophy after losing it to the US 17-11 last time out at Hazeltine.
"I'm excited to take on a slightly different view of things and help the 12 players be as ready as they can to regain this trophy", added McDowell, who hasn't yet ruled out earning a place on the team as a player and has won the French Open twice at this year's venue.
Bjorn said the primary quality of any vice-captain is to 'check your ego at the locker room door, ' and both certainly did a good job of that when officially unveiled on Tuesday, given they're two of the youngest deputies in Ryder Cup history.