Springboks skipper John Smit says the team that wins the Tri Nations will struggle to be crowned World Cup champions eight weeks later.
Smit lifted the William Webb Ellis cup four years ago when South Africa defeated England in the 2007 final. The same year his side finished last in the Tri-Nations with just one win from four matches.
Since the Tri Nations tournament began in 1996, the All Blacks have won the title during the three World Cup years in 1999, 2003 and 2007 but failed to retain their form for rugby's biggest competition.
This year's Tri Nations begins on July 23 and finishes two weeks out from the World Cup which kicks off on September 9.
"There's a fine line because obviously the Tri-Nations is valuable preparation for the World Cup, but you need to be physically ready to add value at the World Cup," Smit told Reuters.
"One perspective is that no team has won the Tri-Nations and then the World Cup in the same year. The peaking scenario is mostly mental, but you have to make sure your body can follow through on that.
"The team that wins the World Cup will be the one that understands the pressure and uses that to their advantage. I think 25 of the 30 players who won the World Cup in 2007 can still go out there and play for us."
Smit said the Super 15 plays a huge part in preparation for the World Cup with player burnout a major factor.
"The Tri-Nations will all depend on how the teams come out of Super Rugby. It's been a different level of physicality and intensity this year, plus the spice added by the local derbies. So it all depends on how your best 30 players come out of that competition," Smit added.
"You would like to field your best XV for the Tri-Nations, but it depends on how burnt-out they are after Super Rugby.
"There's certainly a different stance in this year's Tri-Nations because you want to win it, but it's a helluva tough competition to win at the best of times.
"You don't have much choice, more than 22 players are going to play in it and then you'll see what's left over and what state they're in at the end of it.
Smit, a 102 test veteran, denied reports that South African players have had one eye on the World Cup and paced themselves during the Super 15
"If you hold yourself back then you open yourself up for huge injury risks. There's no room for holding back in Super Rugby because you get exposed so badly if you do," he said.
"We hope we're going the right way and we'll only know after the World Cup. The Tri-Nations is an excellent opportunity to weigh yourself against Australia and New Zealand, two teams that could win the World Cup, just before the tournament starts."
- HERALD ONLINE