Wales' Sam Warburton has been ruled out for the rest of the domestic season after suffering a medial knee ligament injury against Ulster on 7 April.
But the Cardiff Blues flanker is likely to be fit for the British and Irish Lions tour of New Zealand in June.
Lions head coach Warren Gatland names his tour party on 19 April, with Warburton tipped to be captain.
"Sam has a low grade strain which will put him out for approximately six weeks," said Blues coach Danny Wilson.
"It won't interfere with the Lions.
"If we were fortunate enough to make the second European [Champions Cup qualifying] play-off game, we would envisage him being available for that.
"So he shouldn't have any problems regarding the Lions."
Former Blues, Wales and Lions flanker Martyn Williams expressed mixed feelings over Warburton's injury.
'As long as he's up and running for the first Test'
He said: "There will be a concern I'm sure in the back of Sam's mind.
"It's not ideal even though you always look at the positive side of things that there is a break before the tour.
"But Sam Warburton is as professional as they come and I'm sure he'll be fine.
"Ideally as long as he's up and running for that first Test, that's all it's about."
However, another former Wales and Lions flanker, Colin Charvis, said: "It's horrendous timing.
"He's spent a couple of years and then a couple of years building for the Lions and he is in great form at the moment.
"But it's not just Warren Gatland who will look at this - it's the whole Lions management team and will wonder about what they are going to do with Sam Warburton."
Cardiff Blues will be involved in a play-off for a place in European Champions Cup in late May - with the Lions not due to play the first game of their tour until 3 June.
'It's relatively good news' - Blues boss Wilson
Wilson is confident Warburton - who captained the Lions in 2013 but missed the third Test v Australia with a shoulder injury - will recover in time for the tour.
"You see players who get back quickly if they follow protocol through religiously and get a bit of luck and I am sure that will be the case with Sam, knowing how diligent he will be.
"Sam is very experienced and a good pro. He knows his body and knows if he works hard to get that right he will be back relatively quickly.
"He has been fine today. I think it's relatively good news considering how it could have been."
2017 British and Irish Lions tour fixtures
3 June - v Provincial union team (Toll Stadium, Whangarei)
7 June - v Blues (Eden Park, Auckland)
10 June - v Crusaders (AMI Stadium, Christchurch)
13 June - v Highlanders (Forsyth Barr Stadium, Dunedin)
17 June - v Maori (International Stadium, Rotorua)
20 June - v Chiefs (Waikato Stadium, Hamilton)
24 June - v New Zealand (First Test, Eden Park, Auckland)
27 June - v Hurricanes (Westpac Stadium, Wellington)
1 July - v New Zealand (Second Test, Westpac Stadium, Wellington)
8 July - v New Zealand (Third Test, Eden Park, Auckland)
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