Alun Wyn Jones, a Test lock in South Africa, will lead the RaboDirect PRO12 champions the Ospreys into action in Italy against Benetton Treviso on Friday night, while England skipper Chris Robshaw will lead English champions Harlequins into battle against arch-rivals London Wasps in the Aviva Premiership double header at Twickenham.
Heineken Cup champions Leinster kick-off without their Lions, Jamie Heaslip, Brian O'Driscoll, Gordon D'Arcy and Luke Fitzgerald, at the Scarlets, while 2009 tour skipper Paul O'Connell and fellow Irish pack member Stephen Ferris will miss the opening games of Munster and Ulster's campaigns in the RaboDirect PRO12.
Former Lions star Gregor Townsend has taken over as head coach at Glasgow Warriors this season and has assembled a strong squad under former Scottish skipper Al Kellock, while another former Lion, Neil Back, has been recruited as forwards coach at much improved Edinburgh.
But it won't just be in England, Ireland, Scotland and Wales that the Lions Head Coach will be checking out players. There are a host of 2013 candidates playing in the Top 14 in France. They began their season two weeks ago and here is a team worth watching out for:
Overseas Lions Candidates XV: Lee Bryne* (ASM Clermont Auvergne); Aled Brew (Biarritz Olympique), Delon Armitage (Toulon), James Hook* (Perpignan), Iain Balshaw* (Biarritz Olympique); Jonny Wilkinson* (Toulon), Mike Phillips* (Bayonne); Andrew Sheridan* (Toulon), Huw Bennett (Lyon), Gethin Jenkins* (Toulon), Simon Shaw* (Toulon), Luke Charteris (Perpignan), Nathan Hines* (ASM Clermont Auvergne), Johnnie Beattie (Montpellier), Steffon Armitage (Toulon)
* British & Irish Lions
Whoever you support, have a great season, and remember there is only one team to back next summer - the 2013 British & Irish Lions!