The veteran openside has not played this season after he underwent shoulder surgery during the summer. Williams’ last competitive appearance was in the third and final Test for the British & Irish Lions against South Africa on July 4.
But the 34-year-old is now ready to pick up where he left off when the Blues host the Ospreys at the Cardiff City Stadium on Saturday evening. (KO 6.30pm)
Williams has been named in the No7 shirt by Blues coach Dai Young for the massive derby clash with Scott Johnson’s side.
And while his return is great news for the Blues themselves, Williams’ recovery will also be a huge boost to Warren Gatland ahead of the forthcoming Invesco Perpetual Series.
Wales take on New Zealand, Samoa, Argentina and Australia at the Millennium Stadium next month and Williams could now be in line for a starting spot against the All Blacks on November 7.
Elsewhere in the Blues line up, there is a return to the starting side for Xavier Rush, with the Kiwi taking the place of Welsh international Andy Powell who is suffering from flu.
Robin Sowden Taylor picked up a knee injury last weekend at Sale and was not considered for selection, while captain Paul Tito has been given the all clear to play but only trained with the team at the latter end of the week and has therefore been named among the replacements.
Bradley Davies misses out through injury but the young second row is expected to be fit for selection against Leinster next weekend, as is former Wales skipper Gareth Thomas, who is currently struggling with a groin injury.
Blues 15 Ben Blair 14 Leigh Halfpenny 13 Tom Shanklin 12 Jamie Roberts 11 Tom James 10 Sam Norton-Knight 9 Gareth Cooper 8 Xavier Rush 7 Martyn Williams 6 Sam Warburton 5 Scott Morgan 4 Deiniol Jones 3 Taufa’ao Filise 2 Gareth Williams 1 Gethin Jenkins (captain)
Replacements: 16 T Rhys Thomas 17 Gary Powell 18 Paul Tito 19 Ben White 20 Richie Rees 21 Ceri Sweeney 22 Richard Mustoe
