The 36-year-old Gorgie boss is reportedly on his way south for talks with the English Football League club who confirmed on Monday that they made an official approach.
It looks like Neilson, who played under Warburton at Brentford, could be in charge of the Edinburgh side for the last time against the Light Blues.
However, the Gers boss believes the Hearts players will not lose focus as they look for the win that will take them above the Ibrox side and Aberdeen into second place in the Ladbrokes Premiership.
He said: "All I know is I had Robbie at Brentford, he was a top professional as a player, he is a very talented manager and he has a very big future in the game.
"I like him enormously. I am very impressed with Robbie and he has a very bright career ahead I am sure but I am only focused on Rangers and he will deal with what he has to deal with.
"It doesn't (impact), it is about your relationship with the players and I am sure Robbie has a very strong relationship.
"The most important people are the players. We do what we do in our capacity but at the end of the day it is about the players.
"It is an important game tomorrow night and I am sure their focus will be as equally as strong as ours.
"It doesn't affect our preparation, we go there and respect them but it is just about Rangers from our perspective."