The talent show starts its 12th series on ITV tonight and features auditions recorded earlier this year, with the show’s long-time presenters Ant and showbiz partner Declan Donnelly chatting to wannabe stars.
But later in the run – when the live semis and grand final air – Ant will not be involved.
Speaking last night, Simon said: “In times like this you stand by your mates.”
He praised the Geordie star – who last year sought treatment for drink and painkiller addiction – for owning up to his problems and insisted he would never have pulled footage of him from the show.
He said: “I haven’t spoken to him but we always stand by our friends. We are all human. The most important thing is he has manned up, he is going to get himself back together.”
On tonight’s launch show viewers will see Ant crying over one act on stage, saying: “You’ve got me in tears!”
In the final shows Dec will be hosting solo and Simon insisted there was never any question of drafting in someone else to replace Ant. He added: “Dec proved the other day on Takeaway he will deal with it.
“Ant would be a million per cent supportive of this. The show goes on, it’s as simple as that.”
Asked if he would welcome Ant back on to BGT next year, Simon said: “Of course. People, for whatever reason, get into a rut and at times like this you stand by your mates.
“It has always been that way. If Ant needs any help from me, I am there. For Dec, too.”
Ant has split from his wife Lisa Armstrong, who is a make-up artist on BGT.
Music mogul Simon remains loyal to her, too. He said having them both on set had been “awkward” but he made sure he didn’t distance himself from her.
“It was a tiny bit awkward,” he explained. “I’ve known Lisa for years. I spent time with her on my own. I spoke to her to let her know she is still welcome.”
TV’s “Mr Nasty” will be back on the judging panel tonight, along with Alesha Dixon, Amanda Holden and David Walliams.
He has kept the same line-up since 2012 and says he sees no reason to change it.
Simon, who has a four-year-old son, Eric, with US socialite Lauren Silverman, said: “We get on well. I can see them back here next year. If it isn’t broken don’t fix it, I suppose.” l
Britain’s Got Talent, tonight, ITV, 8pm.