Ramadan no burden for Sonny Bill Williams

Blues and All Blacks midfielder Sonny Bill Williams says he's yet to feel the strain from his observance of Ramadan.

The star second-five has been named in the Blues' XV for their clash with the British and Irish Lions on Wednesday, presuming he overcomes a knee complaint that forced him to skip last week's 34-29 win over the Reds.

It's a trying time for Williams, who is in the midst of the Islamic holy month of Ramadan and must fast during daylight, despite his training requirements.

The 31-year-old has tweaked his schedule to make the process, which ends on the day of the All Blacks' first Lions Test on June 24, easier to manage.

"We've got pretty good coaching staff, and trainers as well - I've worked closely with them," Williams told reporters on Monday.

"Getting through the field-based footy is easy, (and) I just push back the weights until the break of fast - thank God in New Zealand, in this part of the world, we only fast for nine hours a day, 10 max."

As someone who has played on the big stage in both rugby league and rugby union, Williams said he was itching to take on the Lions.

Despite their elimination from the Super Rugby finals race, Williams's Blues will continue to build as a squad and throw everything at their Test opponents.

A call up to the All Blacks squad, for whom Williams hasn't played since the side's successful 2015 World Cup tilt, could then be on the cards.

"Coming off a big injury like I have, I'm pretty happy with how I've been going," Williams said, referring to his Achilles tendon rupture at the 2016 Rio Olympics.

"I'm just looking to try and play some consistent footy, get out there as much as I can - it's been a bit stop-start but I'm really excited."