“I know he’s been a Football League manager, and to be fair to Darren, he’s a lovely person, and he was very empathetic towards that situation.
“He understood the conundrum we were faced with. We had planned for Luca [Ashby-Hammond] to play the games, but the red card changed all that.
“We would have been exploring the emergency market had England, and Darren, not been so accommodating.”
Whatmuff, a highly-rated prospect at City, has made 15 appearances for Stockport this season, having quickly reunited with McNulty, for whom he played at Rochdale last term, helping them to promotion via the National League play-off final.
“He [Oliver] was the guy who led it [the decision to withdraw],” McNulty added.
“It means his heart is in the right place towards his team-mates. Essentially putting his team-mates here ahead of his country – I thought that was a brilliant sign of a squad that’s together.”
County are sitting pretty in second place, and three points at the weekend would take them level on points at the summit with table-toppers Huddersfield.
“We have a great respect for Leam [Richardson, Reading boss] and his team,” McNulty added.
“They’re talented, they score a lot of goals, so [it’s a game between] two attacking teams with slightly different dynamics.
“I think it will be a very good game which should represent top League One quality from both teams.”
McNulty also confirmed defender Jay Mingi sustained a “very significant hamstring” injury against Cray on Sunday which has required surgery and he will be missing from first-team action for the foreseeable future.