Pat Murphy considers England's selection options (BBC Radio 5 Live)

McGrath complained of feeling unwell on the final day of the third Test in Adelaide, which Australia won to make sure of retaining the Ashes.

The home side has already been forced to call up inexperienced Matt Nicholson after Jason Gillespie dropped out of their squad with a knee injury.

England have delayed naming their team to give themselves as much time as possible to assess the pitch, but tour management hope the arrival of wives and girlfriends will help lift morale.

A key figure

McGrath: Missed training on Thursday

McGrath has so far taken 16 wickets in the series and Australian captain Mark Taylor is keeping his fingers crossed that his chief strike bowler will be fit for the Test, starting on Boxing Day.

"He's had a week off and he's feeling a lot better, but he still wants to see someone about it because the harder he works the more he feels something in his chest.

"He's gone to get that checked out. It's more precautionary than anything - he could have bowled today in the nets without too much of a problem," said Taylor.

McGrath's health problems increase the chances of 24-year-old Nicholson making his debut after only seven first-class games.

Nicholson: On cloud nine

He joined the squad for practice on Thursday and admitted: "I'm walking on air."

Nicholson took seven for 77 for Western Australia against England earlier in their tour and Taylor said: "I haven't seen a lot of him but I know from what I have heard and what I have seen that he's quite sharp and can shape the ball away from the right-handers.

Mark Taylor on Matt Nicholson (Radio 5 Live)

"In that regard, he's in the Gillespie mould, but whether he's going to be as accurate and as consistent as Jason, I don't know - but we may find out come Boxing Day."

Pakistani ace helps England

Former Pakistan Test player Abdul Qadir is helping England as they prepare for the threat of leg-spinner Stuart MacGill.

Qadir, who took 236 wickets in 67 Test appearances at an average of 32.80 and a further 132 in one-day internationals, took part in England's net session on Thursday along with Lancashire youngster Chris Schofield.

Alec Stewart talks things over with Mike Atherton

England seem likely to recall Surrey paceman Alex Tudor, who may have to bat as high as number seven with only six specialist batsmen likely to be chosen.

Captain Alec Stewart is expected to drop down a place in the order, allowing Mark Ramprakash to bat at number four as he did in the second innings in Adelaide.

Australia's problems are of only marginal concern to tour manager Graham Gooch, who said: "I didn't know about McGrath's illness, but it's not really about who they have got because we know about them and how they play.

Alec Stewart on England's Christmas celebrations

"What we have to address is how we play, and it is clear from the results that we haven't played to our potential so far in this series."