Not all plane sailing for Cullen's South African trek

To cut costs, existing Pro12 teams will only have to travel once to the southern hemisphere but, although they will have their expenses covered by organisers, there will be a limit placed upon the numbers allowed.

With Leinster still likely to be minus their expansive Lions and Irish international contingent, not to mention a host of injured players such as Jamie Heaslip, their squad will be severely weakened for the double-header.

Another stipulation that decrees they would not be allowed to fly out replacements for an injured player could have the capacity to reduce playing numbers further.

"The tournament would prefer that there are less people going because that means less cost," explained Cullen.

"We just have to do what is realistic, even if we have 28 players. For a normal training week, we would like to have 15 against 15.

"We are not going to be able to do that. We've to figure out how we go about it. We train with big numbers.

"The way we manage the group over the course of the season is very different to what other teams would do. It is a challenge.

"We want to be able to manage the players and take a longer-term view with guys who have been away on the Lions.

"I see some of them in other countries are involved in pre-season games. For us, we had five guys on tour. Robbie Henshaw got injured. Johnny Sexton and Tadhg Furlong picked up injuries.

"Seanie O'Brien had picked up an injury. Now, he is back training. Jack McGrath came through pretty well.

When those guys came back, realistically, we talked about them being reintroduced around Round 5.

"Some of them could potentially have been brought back for Round 4. But we are not going to fly those guys out for that. It just presents all these challenges."

Meanwhile, Iain Henderson is hoping that Lions colleague Rory Best's enlightened approach to bonding - English prop Joe Marler claimed at the weekend that he learned to drink thanks to the Banbridge hooker - can help his under-performing Ulster side to get the best out of themselves.

"Those bonds, most of them are made over a few beers, they're very important and Rory was a good driving force behind those," confirmed Henderson.

"We get to go off to South Africa so that's almost like a mini-tour mid season.

"That'll be something all the guys are looking forward to, a few beers out there. You can't forget the social side.

"You have to enjoy each other's company, have a bit of craic, with or without beers and you'll play better. It's a fine line, getting everyone together, making a common goal, and everyone enjoying working towards it.

"We're going to lose at some stage, but it's how we react, how we build from it, and how we move towards the next game."