Graham Rowntree says he does not envisage any problem with British and Irish Lions captain Sam Warburton being available for the opening New Zealand tour game on June 3.

Wales star Warburton has been sidelined for more than a month due to a knee injury, but he met up with 13 of his playing colleagues for a first day of Lions training on Monday.

It is also a possibility that he could feature for Cardiff Blues in their European Champions Cup qualification play-off against Stade Francais in Paris on Friday.

"Sam is on a modified (training) load," Lions assistant coach Rowntree said. "He didn't train with the rest of the team today. He is on a modified load, as you would expect for a guy coming back from injury, but he is going to be fine."

Asked about the Blues game in four days' time, Rowntree added: "That is a bigger picture decision for Sam and the Blues and Warren (Lions head coach Warren Gatland).

"He looked pretty fit to me this morning. I don't think there will be any trouble with him playing, certainly, the first game on tour, but as I keep saying, we are managing him coming back from injury."

Almost two-thirds of the 41-man Lions squad are currently with their clubs, regions and provinces ahead of Aviva Premiership, Guinness PRO12 and Champions Cup play-offs next weekend.

But Rowntree was delighted with the work done on day one in camp at Wales' training base in the Vale of Glamorgan.

"We've got 14 guys here," he said. "Other guys are away in other competitions, which is great, because we want them on the plane going to New Zealand battle-hardened, playing in finals, preferably.

"There was some fitness this morning, then we had a good hit-out this afternoon.

"It has been very useful to get our calls and systems up and running. The lads have got through a whole lot of things very quickly. We have got on with stuff.

"We knew we would be missing a few guys in camp one. We knew what was coming, and we have catered for that.

"We have been getting the guys used to an intensity of how we train. Against the All Blacks, the ball is on the field for a long time, so we trained them hard with that in mind.

"Getting them used to all our systems, from lineout calls to phase plays to how we defend, just getting everyone on the same page. So far, they've done really well."

"Defence is going to be massive for us, but we have to play as well - we have to challenge them"

Rowntree was asked if the players already involved in Lions training would be in pole position to feature in the tour opener against a New Zealand Provincial Barbarians side in Whangarei.

And he added: "Potentially, otherwise we would be wasting the extra time we've got with them, bearing in mind we haven't got a lot of preparation time as soon as we land in New Zealand, so those guys will have a head start, that's for sure.

"It would be good sense to do that. We've got enough combinations here to get some meaningful work done.

"You don't need your full quota to get your systems up and running.

"They (New Zealand) are a difficult team. The ball is on the field for a long time. Defence is going to be massive for us, but we have to play as well - we have to challenge them."