Berry was stretchered off in last Friday's game against Colchester, with the midfielder in good spirits ahead of an operation planned for tomorrow morning after seeing a specialist on Tuesday.
(Luke thanks all the well-wishers as he begins his recovery from injury)
Jones said: "He saw the specialist on Tuesday. He will have an operation to amend [the damage] – it's ankle ligaments that's the main thing. He's had a minor break, I think it's the fibula which is the non-weightbearing one, I think, my medical knowledge isn't the highest.
"It's not the worst news, but it's not great news. It's going to be a medium-term injury, medium to long in terms of the months that he's going to be out.
"But we will make sure he gets the best medical advice and make sure he recovers to get him back as quickly and as safely as possible. It's an ankle injury, the ligaments are going to take time to heal. He is having an operation on Friday morning and his recovery starts then.
"He seems very good at the moment [mentally]. He has got very good support around him. I think it's sunk in now and he realises as a professional athlete, there's two choices, two mindsets; you either wallow and really feel sorry for yourself and go backwards or you think 'right this has happened, what do I need to do to move forward'.
"Luke is very much of the latter, 'right I am going to work, I am going to come back stronger', which you need to. It's a mental thing as much as a physical thing to recover because you have to have positive thoughts and the mindset to work hard.
"Medical science has evolved – this is a bad injury, but it's nowhere near as bad as it was years and years ago. We are looking to get him back in the medium term. We won't see him again this season and through pre-season.
"The only godsend is it's late in the season – two-and-a-half, three months of his rehab time will be done without a competitive game. So it's better he does it now rather than in December or November or September, because then you miss chunks of a season. But that won't be the case with him."
The gaffer was also pleased to see five of his players make up the League Two team of the season, although he joked he would have liked to have seen more of his players in there, given how well he feels some of them have got on during the 2017/18 campaign.
"It's phenomenal," the Welshman continued. "To be voted for by managers, it's phenomenal. Ironically, a bit greedily you'd have hoped to have a few more, because there's been some good ones you know. You look at Marek's form. You look at people like James Collins that have been absolutely outstanding all season, he's one of the top scorers in the league and how he plays. He's been unfortunate.
"But to have more than five would be greedy. It's unprecedented to have that many, especially with the quality of the individual players, so we're very, very pleased. Having three out of your back four in the team, it's a big thing."