Alan Shearer admitted on Tuesday night he 'fears the worst' after a scan on his injured knee had to be postponed for 24 hours.
Shearer suffered a suspected tear of his medial ligament during Newcastle's 4-1 victory over Sunderland on Easter Monday.
The swelling around Shearer's left knee has forced the scan to be delayed until Friday and the Newcastle captain is not holding out much hope.
Shearer plans to retire at the end of the season - but confirmation of ligament damage would bring his illustrious career to a premature end.
'I am fearing the worst unfortunately. I have been injured before plenty of times so I know the scenario and I haven't got a great hope,' said Shearer.
'It's a matter of time. We have to wait and see and let nature take its course and hopefully the scan will reveal on Friday the damage is not too bad.
'Over the years my glass has always been half full and not half empty.'
Shearer still hopes to make one final appearance at St James' Park to thank the Toon Army - at his own end-of-season testimonial match against Celtic.
'I will try hard to do it. Newcastle is my club and always has been. I've had 10 wonderful years here,' he said.
'I have not given up hope yet, hopefully I can play a small part in the testimonial. All the tickets are sold and the money is going to charity.'
Shearer, who was tonight presented with the HMV Lifetime Achievement Award at a gala dinner in London, leaves the game with no regrets despite a decade at Newcastle without a winners' medal.
'I have had a great career, I can't complain. I have been a lucky boy,' said Shearer.
'I have never been one for looking back. I have had a fantastic time, I've been more lucky than many other people have and I have lived my boyhood dream, scoring goals in the number nine shirt.
'The undoubted highlight has been winning an England cap, winning the league at Blackburn in the way we did and playing for my club Newcastle.
'I had always wanted to do that as a boy, to score at the Gallowgate End as captain.
'I have hoped more than most to win things at Newcastle. But I have given my all and no-one can ever take that away.'
And if Monday's game is to be his last?
'It wouldn't be a bad way to sign off, scoring on my last game and beating Sunderland 4-1,' he said.
Shearer confirmed he plans a clean break from Newcastle at the end of this season and is not considering staying on a coaching capacity.
'I want some time for myself first,' he said.
'One day I'd like a bash at management, I am doing my badges at the moment but I want a few years off to enjoy life first.'
Previous recipients of the HMV Lifetime Achievement award include Sir Alex Ferguson, Sir Bobby Charlton, Brian Clough, Nat Lofthouse and Sir Stanley Matthews.
Ferguson hailed the 'great courage' Shearer had shown throughout his career - and insisted he did not begrudge the former England skipper's refusal to join Manchester United.
Shearer has battled back from career-threatening knee and ankle injuries and a broken leg to write his name in the Premiership history books.
Ferguson said: 'Alan is the professional's professional. The great thing about Alan is that he's had some serious injuries.
'It takes a lot of determination and will to get back from serious injuries but he has done it a number of times.
'That's the hallmark of someone who has great courage. Unfortunately he might not finish the season but this injury has just come at a bad time for him.
'He's just come back from a big injury and had a great period of playing. Some players can't do that but Alan has.'
Ferguson tried to sign Shearer in 1996 but instead the England marksman chose to leave Blackburn for home town club Newcastle in a then world record £15million deal.
Ferguson said: 'There are no hard feelings that he turned Manchester United down. Football is football. I'm sorry he didn't join us but there you are.'
Shearer's 206 goals in 395 starts for Newcastle has made him a Toon legend while his 30-goal international haul has afforded him hero status among England fans.
The 35-year-old has arguably been the Premiership's greatest striker and Ferguson highlighted his accuracy and consistency as the reasons behind his success.
He said: 'Alan's a centre forward. In an era when the game is changing in terms of terminology of what a player is, he's a centre forward.
'He's a natural centre forward in the tradition of the British game.
'It's not easy for the lad because as the changes of game have come along the roles of players have changed, but he's never changed as a centre forward.
'The memory of Alan is his percentage of shots on target. If there was an opportunity to have a strike at goal he would get it on target.
'That was a great asset he had and stood him apart from other centre forwards.'