Vieira and former Arsenal team-mates Dennis Bergkamp and Thierry Henry supported Spotify founder Ek’s takeover bid in April following the club’s involvement in the failed European Super League project.
Stan Kroenke, who owns the club through his Kroenke Sports and Entertainment business, rejected the offer but Henry said last month that Ek remains fully committed to buying Arsenal and "we and he is here to stay".
Former Arsenal captain Vieira was subsequently appointed Crystal Palace manager in July and is set to make an emotional return to north London on Monday night.
"I was just expressing myself as Patrick, ex-Arsenal football player," Vieira said when asked about his support for Ek’s takeover plans ahead of Palace’s Premier League visit.
"That comment was based on how the direction (of the club) was going.
"I was talking to somebody who had a different view and a different way of taking (forward) Arsenal Football Club.
"This was the reason why with Dennis and Thierry we were involved in the kind of situation that Arsenal was in.
"I am in a different position than a couple of months ago. So I’m not going to express myself in the same way than when I was just an ex-Arsenal football player."
Henry confirmed in September there was "no dialogue" between the Kroenke family and Ek over a potential change of ownership at Arsenal.
But Henry, Arsenal’s record goalscorer, indicated the deal was not dead, saying: "It hasn’t happened yet, but we and he is here to stay. So let’s see what’s going to happen."
However, Vieira said: "?When you were looking at the situation at the time it was clear that the Kroenke family was making the statement that the club is not for sale.
"Then I think everything was over. You can’t buy a football club if it is not for sale."