The Manchester United winger was carried off on a stretcher on Tuesday during United's Champions League 0-0 draw with Rangers after suffering an horrific injury following an innocuous incident involving Kirk Broadfoot.
Initially, Ferguson said Valencia would miss the remainder of the campaign. However, it now appears the damage is not quite as bad as the United boss feared.
Big worries: Wayne Rooney looks on as Antonio Valencia is treated on Tuesday night
'You can never be 100% accurate inthese situations and it is a bad injury, but we are looking at the endof February, which is better than we thought on Tuesday,' said theUnited boss.
Valencia had an operation on Wednesday evening to put his left ankle back into place after it was fractured and dislocated.
Ferguson revealed the Ecuador star had also suffered some ligament damage.
'The operation has been successfuland the break was clean, which was the major concern for us at thetime,' he said. 'He is a strong boy, who is very positive about it.
'Being positive helps you in these situations, so we are very hopeful we will get him back then.'
Ferguson, who has no other injuryconcerns ahead of Sunday's blockbuster duel with Liverpool at OldTrafford, accepts the loss of Valencia is a significant blow.
Nightmare: Valencia suffered the double break after catching his studs in the turf
However, in Nani, Ryan Giggs and Park Ji-sung, plus to a lesser extent Gabriel Obertan and new-boy Bebe, who made his reserve team debut last night, he feels United have the options to cope.
'Antonio had a great season last year,' he said. 'He was a great signing for us. He is a young player who has been improving all the time.
'It is a blow losing good players but in the context of the kind of squad we have, we should be able to cope with it. You always fear when you have a good player out of your team it is going to be a loss.
Horror: Kirk Broadfoot can't bear to look after the incident at Old Trafford
'But having players like Nani, Ryan Giggs and Park Ji-sung, plus Gabriel Obertan and Bebe means we have options.'
What will benefit Valencia as hebegins the long fight for fitness is a positive mindset. That was neverbetter exemplified than by Alan Smith, who suffered similar misfortuneduring an FA Cup tie at Liverpool in 2006, but whose mental toughnessastounded even Ferguson.
'There is a mental part to it,' hesaid. 'Take the example of Alan Smith. When Alan got his bad injury inthat cup tie against Liverpool, he was so positive.
'He sat in that treatment room atAnfield so nonchalant and relaxed about it. Yet you look at his ankleand think 'God almighty'. That attitude definitely helped him.'
VIDEO: Fergie on Valencia's return. Valencia's operation hailed as success with crocked winger in good spiritsThank Roo! Rangers star Broadfoot grateful for Rooney's wordsSmith relives his injury nightmare and tells crocked Valencia: You'll be backMANCHESTER UNITED FC