Jones came off in the 20th minute of Wednesday’s 5-0 win at Fulham after being caught by a stray Clint Dempsey elbow, but Sir Alex confirmed there was no break to his jaw.
Young limped off midway through the second period at Craven Cottage with a knee injury sustained in a heavy tackle by Dickson Etuhu, having stumbled following a challenge by Chris Baird.
"We have good news on Phil Jones: he should be okay for Monday," the boss said. "He has some swelling in his jaw but there's no break, no fracture, which is good news.
"We feared the worst because he lost his vision a bit in that period when he came back onto the field. Thankfully it's good news.
"It's not so good for Ashley Young. We're still waiting on some of the bleeding to go away, which is quite extensive at the moment. It was a sore one so he'll be out for a few weeks.
"Ashley was tripped as he went into the next tackle. He wasn't positioned to go into that next tackle – he was half-falling at the time.
"The second tackle was a hard tackle – not a bad tackle – it was just the way he went into Ashley. He's taken a real clump."
Rafael is in back in contention, but Michael Owen, Tom Cleverley and Anderson are also all still sidelined. Nevertheless, Sir Alex feels his side have coped with the injury situation well in recent weeks.