The Spaniard has missed United’s last seven games after undergoing surgery on a hernia last month.
Mourinho feared the playmaker would be unable to return during the current campaign but Mata has provided a promising update to United fans.
‘As you can imagine, this month has been a bit too long for me due to my injury,’ Mata said in his weekly blog.
‘I had never been in a situation like this before. I’ve been very lucky.
‘But the truth is I’m feeling much better now and I hope to be back with the team soon, to try to help in the last spell of the season.
‘I hope so, because that’s all I want: being always available to help and to contribute as much as I can, both on and off the pitch.
‘A million thanks for all your messages wishing me a speedy recovery, I’m getting closer!’
United have won their last three games in the Premier League to close the gap on City to just one point.
Mourinho’s side take on their fierce rivals on Thursday evening and Mata hopes the Red Devils grasp the opportunity to move into the top four.
Manchester United boss Jose Mourinho has had to deal with several injury setbacks this season (Picture: Getty)
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The 28-year-old added: ‘There’s no truce in the calendar and this very Thursday there’s one of those games that every player likes to play: the Manchester derby.
‘Away this time, but we know that, with the top of the table so tight, this is another big chance to make an important step in our fight and keep climbing.’