Phil Jones missed the open section of Manchester United training at Carrington on Monday morning ahead of Tuesday night's Champions League meeting with Real Madrid.
Jones has been a fitness doubt after injuring his ankle in the FA Cup win over Reading a fortnight ago, although manager Sir Alex Ferguson has vowed to give the England man every chance of making the last 16 second-leg clash at Old Trafford.
Jones' absence is not necessarily an absolute indicator of his chances of facing Jose Mourinho's men, although clearly it is not a positive situation either.
With Jonny Evans training on his own at the start of the session rather than involving himself in the normal keep-ball routines, Ferguson drafted in two reserve-team players to make up the numbers. Former Charlton trainee Sean McGinty and midfielder Luke Hendrie were the lucky players, but it would be a major surprise if either played any part on Tuesday.
Club director Avi Glazer was also present as the build-up to one of the most eagerly-anticipated European games stepped up a notch.
United midfielder Michael Carrick acknowledges evenings like Tuesday night are the ones that really get his competitive juices flowing. After almost seven years at Old Trafford Carrick has enough experience not to be overwhelmed by the biggest of occasions. But he accepts certain matches are beyond the norm.
"These are the nights you live for," he said. "It is extra special. There is just something in the air. Everyone comes to the stadium with a spring in their step. Every supporter is that little bit more vocal. They appreciate how important it is and what it means to get through.
"The prestige and history of the club suggests we should be challenging in the later stages of these tournaments.
"It is up to us to go out there and do it."
Iker Casillas' presence in the 24-man Real Madrid squad that flew into Manchester on Sunday night underlines the importance being placed on the game by Real boss Mourinho given the vastly experienced goalkeeper has been missing since January, when he fractured his hand against Valencia, and only returned to training on Thursday.