John Souttar, Ben Woodburn and Beni Baningime are all available for Wednesday night’s Premiership fixture, although Taylor Moore is again expected to be absent.
“We have everyone back training apart from Taylor Moore, who has a small thigh problem. We will hopefully have him back for the game against Motherwell on Saturday,” said Neilson.
“We almost have a full squad to pick from including John, who still has a slight issue with his ankle. I still expect him to be ready for Wednesday.”
Souttar missed Saturday’s Scottish Cup win at Auchinleck Talbot, Baningime was an unused substitute after a knee problem and Woodburn was out with illness.
“Both [Baningime and Woodburn] are fit and both trained full training on Sunday and Monday. They will both be available for the game on Wednesday,” said Neilson, still working on new signings before the January transfer window closes.
“We are trying to get boys back from injury and we are trying to get a few in as well. We decided at the start of the season to go with quality over quantity. A lot of teams will run with 20 players and maybe only 12 or 14 are up to standard. We decided to go with 16 that are really good.
“There will be times when with injuries and suspensions we are down to the bare bones but we decided to do that. It’s easier to manage, miles easier. There are two sides to it. Part of it was that and part of it was financial. We don’t have the Old Firm budget but we’ve got enough to get good players in.”
Souttar’s immediate future remains uncertain after Hearts rejected a £300,000 offer from Rangers for the centre-back, who has agreed a pre-contract with the Ibrox club. Neilson confirmed there have been no further bids.
“There’s been nothing else. I don’t think it will be a distraction,” he said. “We have got a massive game on Wednesday and we have another one on Saturday [against Motherwell]. So from our perspective there is no distraction. John is a Hearts player and he will continue to be a Hearts player until things change.”
Asked if it was difficult to prepare for the Celtic match knowing another offer could come in at any moment, Neilson replied: “For all the downsides of Covid, one of the upsides is you need to think on your feet. You never know day to day who is going to turn up for training. It’s the same for games.
“We had it a couple of weeks ago when we had done all our work then we had two boys out with Covid on the Saturday morning. You just need to adapt. It’s the same situation when players are coming or going. You take it daily.
“We have a good squad who know the formation we play and know their roles. It makes it a lot easier to bring guys in and out.”