Kev Leaving But Anderson Positive
McNaughton had already knocked back an offer to stay at the Dons last year and was being touted around Premiership, Championship and tiny Norwegian clubs by his agent John Viola with no avail.
Super Kev now faces life in the lower divisions of England or elsewhere, and may even be forced to endure a season without a club.
Dons manager Jimmy Calderwood told the Press & Journal: "Kevin came to see me and told me he will not accept the contract offer from the club.
"I didn't tell the players of Kevin's decision until after Saturday's game against Hibs as I wanted all our efforts to be focused on getting the win we needed to secure our top-six place.
"Now we have done that, though, we can prepare for life without him and step up our search for his replacement.
McNaughton has finally picked up his game in a mostly disappointing season since joining Russell Anderson in the centre of defence and the Dons captain would have liked to continue their partnership.
Anderson said: "I would love to see Kevin stay at Aberdeen because once again this season he has proved how important a player he is for us.
"I think we would have to sign two players to replace him because of his versatility and he always looks comfortable whatever position he is in.
"He has the ability to play anywhere across the defence and has done really well over the last few weeks since he moved to centre-half."
Meanwhile, Russell was delighted to have beaten Hibs to get into the Top Six for the second season running under Calderwood, and is now looking to continuing the Reds' 2006 climb up the table.
He told the Press & Journal: "It was a huge result for us. It turned out we did not need to win but that was not the important thing.
"We needed to try to get the three points after last week's win against Caley Thistle, get some momentum and try to get a run of results through to the end of the season.
"People may still say we have nothing to play for, they said that after we went out of the cup to Hearts, and it was said we would not be able to make it into the top half of the table.
"We have been written off for fourth place, and we still have a lot to do, but the fact is we have to play Hibs and Kilmarnock. There will be points dropped and, although we are still an outside bet to do it, we can look beyond the top six now."