After spending almost two years trying to recover from a career-threatening tendinitis problem in his knees, Hargreaves thought he was on the comeback trail last season.
The 29-year-old managed a 45-minute reserve team outing before coming on for the final few seconds of the Premier League win over Sunderland in May.
At that stage, it seemed as though Hargreaves would play a major role at United this season and there was even talk of an unlikely call into Fabio Capello's World Cup squad.
As it turned out, Capello was advised to look elsewhere and when Hargreaves started experiencing pain during the early stages of pre-season training, he was sent back to Dr Richard Steadman in Colorado for more rehabilitation work.
Hargreaves is due back at United's Carrington training complex at some point this month, after which it will be down to Sir Alex Ferguson to decide when to push his recovery programme towards competitive matches,
"Things are looking good for Owen, it's all worked out," Steadman told the BBC.
"He's close to playing fitness, although it's obviously up to United to decide when he plays a match."
A £17million signing from Bayern Munich in 2007, Hargreaves is now in the final year of his United contract, although Ferguson would want to see hard evidence of the player's improvement before he thought about offering an extension.
"The problem was with the tendon attached to the patella on each knee, which is difficult to resolve," added Steadman.
"After the surgery, the key was rest and working hard on recovery.
"Owen has spent a lot of time with us here in Colorado and he has never given up.
"The recovery was arduous and took a long time but his condition looks promising now."
Although Hargreaves was omitted from United's 25-man Champions League squad, the Calgary-born star is available to play in the Premier League and also both domestic cup competitions.