The young Brazilian had been bossing the Boro midfield in September's third-round Carling Cup tie when he was crudely cut down by Emanuel Pogatetz.

An instant red card followed, with a humble apology coming from Teesside the next day once the severity of Pogatetz's challenge had become clear.

By then, X-rays had established there had been no leg break, as Ferguson initially thought, but some sort of ligament damage seemed certain once the swelling from a nasty gash had gone down to allow a full diagnosis.

Remarkably, Possebon had not suffered that either, leaving him free to continue a career that has shown immense promise since the 18-year-old arrived from South America in January.

"We did worry," admitted the United boss.

"When I saw Rodrigo going off, it did not look like he would be seen again for quite a while.

"But there was no problem with the boy. He is a terrific kid and his temperament is excellent, which allowed him to get over it."

For the next instalment of the Carling Cup, Possebon will be joined by Jonny Evans, Darron Gibson and striking pair Manucho and Danny Welbeck against QPR as United look to secure a place in the last eight of a competition they won as recently as 2006, when they hammered Wigan at the Millennium Stadium.

The form of Angolan hitman Manucho and England Under-19 international Welbeck - who has struggled with a series of injury setbacks this term - will be of particular interest, even if Ferguson has plenty of experience on hand in case of trouble.

Welbeck is regarded at Old Trafford as a player of high potential, even more so that Frazier Campbell, who is currently on loan at Tottenham.

The Macclesfield-born youngster knows Ferguson will not be scared to give him a chance if he shows enough promise, with evidence coming in the form of 18-year-old full-back Rafael Da Silva.

Rafael arrived with twin brother Fabio and Possebon as United's search for young talent took on a global dimension.

Although it was felt all three would have to be patient in waiting for their first-team opportunities, Ferguson has recognised the extreme talent in his midst.

Rafael is now pushing skipper Gary Neville and currently-injured England international Wes Brown hard for a regular starting spot.

Ferguson credited Rafael with providing the lead that eventually resulted in the Red Devils snatching a precious Champions League point off Celtic at Parkhead last week.

And then on Saturday, he belted home his first senior goal, even if it was not enough to stave off defeat at Arsenal.

"At Celtic, Rafael got a warning from the referee for the first tackle he made, when he brought down Shaun Maloney. The crowd reacted as though he had chopped the boy in two," observed Ferguson.

"For 10 minutes the little lad was unsettled, which is understandable at 18. After that he was absolutely brilliant.

"I was delighted an 18-year-old lad could do that.

"He has such character and talent - and great courage. He has got that Brazilian mentality. He wants to get on it all the time."

The pair are likely to be team-mates at Old Trafford on Tuesday night as Ferguson uses his experienced players to fill the holes.

Darren Fletcher, Nani and Anderson will probably be involved in some capacity, while 18-year-old James Chester may profit from Brown's absence, which leaves Ferguson short of defensive cover.

After handing Ben Foster his first Champions League start in Glasgow, Tomasz Kuszczak will be in goal as Ferguson pursues a policy of rotating his back-up keepers when 38-year-old Edwin van der Sar is rested.