Aston Villa manager Paul Lambert admits he still seeks advice from Sunderland boss Martin O'Neill despite them being rivals.
Lambert captained Celtic during O'Neill's reign at Parkhead, helping the club to three SPL titles as well as reaching the Uefa Cup final.
O'Neill knows all about Villa having coached them from 2006 to 2010 and Lambert has revealed his former manager contributed to his decision to leave Norwich this summer.
"I phone the gaffer because he's been in it longer than me and I always think if I could get a smudge of his success, just a little bit, I'll be doing all right," he told the Birmingham Mail.
"There have been times when I've phoned him up for advice, and I spoke to him before I came.
"He said it is a brilliant club, with a massive fan base and never dissuaded me one bit. Not one iota.
"I think he had a good time here, had a lot of success and had the place absolutely rocking, so if I need help I'll definitely give him a call.
"I don't have any problem making mistakes - I just need to learn from them.
"There are certain times when I'll need a bit of help and I'll phone him up and ask 'can you help'."