Johnny Sexton must come through 'modified training ' to prove his fitness for Ireland 's pivotal RBS 6 Nations clash against Wales in Cardiff . Ireland 's lynchpin fly-half has 'hit all his markers so far ' in battling hamstring trouble , but is still fighting to recover to face Wales on Saturday , according to team manager Mick Kearney . Number eight Jamie Heaslip was due to take contact training on Monday for the first time since fracturing three vertebrae in his back against France on February 14 . Ireland 's Johnny Sexton is winning his battle to be fit to face Wales in the RBS 6 Nations on Saturday . The Leinster stalwart is now expected to be fit to face Wales , where victory would leave Ireland almost nailed-on for the Grand Slam . 'Johnny Sexton continues to improve following a mild hamstring strain , ' said Kearney . 'As a precaution he will have modified training during the early part of the week with an expectation that he will train fully towards the end of the week . 'We are very happy where he is at , at the moment . He has hit all his markers so far . 'Johnny will have modified training in the early part of the week and if he comes through training through the latter part of the week , he will be available for selection . Sexton has come through all the tests asked of him so far but there is still a chance he could miss the game . 'Jamie Heaslip is expected to train fully this week and barring any setback will be available for selection . 'Sean O'Brien and Jared Payne have both progressed well through the return to play protocol and will be re-introduced to full training during the week . 'Johnny will have modified training today . Jamie will train fully today . ' Team manager Kearney admitted British and Irish Lions Sexton and Heaslip are both 'extremely eager ' to face Wales this weekend . Ireland are gunning to retain the Six Nations title for the first time since 1949 , and also claim a second Grand Slam in six years . Sexton limped out of the latter stages of Ireland 's 19-9 victory over England in Dublin on March 1 and has been battling to recover ever since . The 29-year-old has a history of hamstring problems , but Kearney does not expect that to colour his recovery . Jamie Heaslip is expected to train fully this week and barring any setback will be available for selection . 'From what I remember the last time he had a problem was between the Australia game and New Zealand game , in the November series just over 12 months ago , ' said Kearney . 'He actually recovered pretty quickly then . 'He came off at half-time against Australia and was fit to play and played the whole game , or most of the game against New Zealand without any issue . 'That certainly would n't be a worry at the moment . 'Jamie ( Heaslip ) has n't taken any contact yet . He will train fully today and provided there is no reaction he should be available for selection . 'They are extremely eager , absolutely : very eager to play . ' Fit-again Ulster lock Dan Tuohy has been drafted back into Ireland 's wider 36-man training squad . Fit-again Ulster lock Dan Tuohy was drafted back into Ireland 's wider 36-man training squad for the final two weeks of Six Nations action . Ireland must win in Wales and Scotland to secure the Grand Slam and retain their Six Nations title - but , barring injury , will do so without veteran centre Gordon D'Arcy . The 35-year-old Leinster centre has been omitted from Schmidt 's training squad , with Ulster 's Darren Cave and Munster 's Keith Earls providing midfield cover . Team manager Kearney refused to accept D'Arcy 's absence could spark the end of his glittering 81-cap Test career however . His long-term centre sparring partner Brian O'Driscoll retired last summer , but D'Arcy himself has always been determined to push on to this year 's World Cup . 'That is a selection issue , yes , ' said Kearney of D'Arcy 's absence . 'Gordon has been an unbelievable servant for Irish rugby . 'He 's back fit , back playing for Leinster , so certainly I would n't rule him out for future consideration . ' Both teams must give consent for Saturday 's Millennium Stadium match to be played under a closed roof . Team manager Kearney said Ireland will delay their decision until later in the week , and base it around the chances of rain . 'We are waiting to see what the weather forecast turns out like , ' said Kearney . 'We do n't have to make a decision on that until 7pm on Thursday . 'We will wait until then before we make a final decision . ' I think overall , our preference would be for a dry day and decent weather , rather than wet and miserable weather . 'In good weather our preference would be for it to be open . '
One - half mark brown has ' lost all his markers ' in battling hamstring issues . He is expected to be fit for trials with Wales to achieve Grand promotion hopes . Team manager Mick Kearney says there is still a chance he will not be fit .