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 tomorrow.
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 nights like tomorrow are the ones that really get his competitive juices flowing.
After almost seven years at Old Trafford - during which time he has won four Premier League titles, won one Champions League and played in two other finals - 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.
Yet Sir Alex Ferguson's love of European combat means United will be fully primed for a task that includes stopping former Red Devil Cristiano Ronaldo, who returns to his old club for the first time since his £80million move to Spain in 2009.
"Cristiano pretty much has everything," Carrick said. "He can shoot with both feet. He can cross with both feet. His ability on the ball is exceptional. He can manoeuvre the ball and generate space for himself, and we have saw in the first leg how good he is in the air.
"You just have defend as best you can, work as a unit and help each other out."
Though a goalless draw will be enough to send United through after last month's 1-1 draw at the Bernabeu, Ferguson has ruled out the potential for such a scoreline given the strength of both teams lies in their offensive potential.
It is not an assessment Carrick wishes to dispute.
"Look at both teams," the England international said. "We both attack well and have all the threats that can create and score at any given time.
"That is the nature of the tie. Even though you might be defending well, you can never switch off.
"We had chances in the first leg and so did they. Either team could have won 2-1 or 3-1. It is going to be about who takes their chances on the night."