CHASKA • Olympic swimming star Michael Phelps delivered a message on competing for the country to the United States Ryder Cup team, while Irish rugby legend Paul O'Connell is supporting Europe's "shoulder to shoulder" theme.

Retired celebrity athletes from other sports making speeches to teams, a Ryder Cup tradition, brought early support to their sides at Hazeltine ahead of tomorrow's 41st edition of the biennial men's golf tournament.

"I kind of talked about how swimming's an individual sport, but when we come together as a team, we really do come together as a team like no other country," Phelps said. "No matter where we're from, we're all together. I think that's something that's really cool for me to be a part of."

The 31-year-old, who spoke to the American squad on Monday , won a record 23 golds plus three silvers and two bronzes over five Olympic trips, including five golds at last month's Rio de Janeiro Games.

"Michael talked to us a lot about the Olympic experience and Team USA and how much fun it was for him to have the four American golfers (in Rio) as he's such a big golf fan," US captain Davis Love .III said.

O'Connell, a 36-year-old former lock, played 108 international matches for Ireland, captaining his national side as well as Munster and the British and Irish Lions in 2009 and 2013.

"Everyone I've ever spoken to who has heard Paul address teams says he's seriously inspirational," Europe captain Darren Clarke said.

"I feel very fortunate and privileged that he's there to join us."

Clarke emphasised a "shoulder to shoulder" unity theme taken from Irish rugby song "Four Proud Provinces" played before Irish national rugby matches.

The lyrics tell of Ireland and Northern Ireland players coming together as one team - "Ireland, Ireland, together standing tall, shoulder to shoulder, we'll answer Ireland's call."

It was Clarke's call that O'Connell answered for a Tuesday night talk and the rugby star will try to help Europe win on the road to capture an unprecedented fourth consecutive victory over the Americans.

"Shoulder to shoulder, it resonated with me," Clarke said. "It was something I pursued through my captaincy. There's no finer example of shoulder to shoulder than Paul O'Connell. He has legendary status at home and in terms of leading the British Lions, who always play away from home."

Clarke also made certain that O'Connell's background was not lost on players such as Spain's Rafael Cabrera Bello and Belgium's Thomas Pieters from nations where rugby is not as huge as it is in Britain and Ireland.

"Yes they have (heard of him) because they have been made aware of a few things," Clarke said.

AGENCE FRANCE-PRESSE, NY TIMES