America's Cup: We must be cautious about a change - Coutts

Ben Ainslie was on board Oracle Team USA today, a hint that he will take over as the team's tactician.

Speculation is mounting that Oracle Team USA have rung in the personnel changes aboard the boat with British Olympic hero Ben Ainslie sighted on USA-17 in today's training run.

Oracle are back out on the water in San Francisco today, using the rest day in the Cup to try and finetune their boat-handling and systems as they fight to get back into the 34th America's Cup match.

Sensing the regatta slipping away from them after another big loss to Emirates Team New Zealand in yesterday's fifth race, Jimmy Spithill's crew opted to play their postponement card in race six, pulling up stumps early and heading back to the sheds to re-group.

While Spithill said team need to examine how they can eke more speed out of their boat, he also didn't rule out changes to the crew. The team's tactician John Kostecki was considered to be the one most likely to be in the firing line. Kostecki, a San Francisco native and one of the few American sailors in the Oracle crew, has been out-witted on his home waters by Team NZ.

With Ainslie out training with the team today and no sign of Kostecki, it appears Oracle have gone ahead and made changes to their afterguard.

Syndicate CEO Russell Coutts said skipper Jimmy Spithill will make the decision.

"You've got to remember, changing personnel at a time like this has never worked in the past so we've got to be cautious about making a change like that,'' Coutts told The Associated Press. "We wouldn't be thinking about it unless it had a really good chance at working.''

Coutts said Ainslie has the ability to make a difference.

"He's obviously an extremely accomplished sailor, but Jimmy and Ben and Tommy Slingsby haven't worked together yet,'' Coutts said. "That's a pretty big ask at this point in the regatta.''

Ainslie, who helms Oracle's 'B' boat, last night told Sky Sports UK he would be prepared to "step up" to the challenge if asked.

"For me personally it's about being part of the team, I'll do whatever the team wants me to do. If the decision is made that they want me to sail on the boat, of course I'd love to do that," the five-time Olympic medallist said.

"But at the same time I came into this team aware that my role was to support Jimmy Spithill and helm the second boat and I've been happy to fulfill that role, but if that changes then I'll step up to it."

Oracle have until 9am tomorrow local time to notify officials of any crew changes. Racing resumes tomorrow with a further two races scheduled.

Team NZ lead the first-to-nine series 4-0, with Oracle still to clear one penalty point before they can start scoring.

This morning's front page of the New Zealand Herald: