Hearts are ready to field John Souttar against Celtic as the defender returns from the injury which kept him out at the weekend.
The centre-back has signed a pre-contract deal with Rangers and was roundly booed by the home fans in the win over St Johnstone at Tynecastle.
The Premiership champions are aiming to bring Souttar to Ibrox this month but had a first offer rejected by Hearts.
And the Scotland international will be in the team to face Celtic on Wednesday after missing the Scottish Cup win over Auchinleck Talbot with an injury.
Neilson said: "John trained (on Monday) so he will get a bit of treatment on his ankle and I expect him to be available for Wednesday."
Souttar has signed a pre-contract agreement to join Rangers and it remains to be seen whether the Premiership leaders will return with another offer in January.
"We shall wait and see," Neilson said. "There was an offer, it got knocked back, and that's it done.
"We are just focused on the game, all eyes are on Celtic now. It doesn't really bother us at all."
Hearts are looking to repeat their opening-day win over Celtic and Neilson has urged his players to set their sights on catching Ange Postecoglou's side.
"Celtic are very, very good team but we have a home game against them now, and if we can pick up three points we will go within six of them and it keeps us closer," he said.
"We speak to the players all the time about looking up the way and not looking behind us. If we can aim for the two teams at the top of the league, we don't need to worry about what's coming behind.
"We got a great result at the start of the season and we hope to do it again.
"We will have 19,000 Jambos there and it will be a brilliant atmosphere. We believe we can go and win and if we get a result it sets us up for the next few games, which will be tough.
"We have to play to the best of our ability, we understand that, but we have managed to do that a few times this season."
