Cesc Fabregas completed his move to boyhood club Barcelona on Monday and Nasri has been tipped to follow the Spaniard out of Emirates Stadium.
Nasri is in the final season of his Arsenal contract and has been heavily linked with a move to City after United had a bid rejected earlier this summer.
The France international was not involved in the Gunners' opening game of the season against Newcastle due to illness and Wenger is keen to hang on to the midfielder.
"The two things are not linked in my spirit," said Wenger when asked if Fabregas' departure made him more determined to hang on to Nasri.
"Ideally I want Samir Nasri to stay, but as much as we were in a strong position on the contract side with Cesc, the situation is a bit different, but hopefully we can sort the situation out."
When quizzed on a scale of one to 10 how confident he was of keeping Nasri, Wenger replied: "I don't like the scales in the game because it's always not very predictable.
"It's very difficult to answer that question in an honest way."
The Arsenal boss is also not concerned about the message that would be sent out to the club's Premier League rivals if he does persuade Nasri to stay in North London.
He continued: "What is more important than the message is how strong we feel inside as a team.
"We are determined, we have bought some very good players and, overall, the feeling inside the squad is very strong, and the desire and belief is very strong.
"But, of course, we will be encouraged by the results that are made in the very near future, and certainly by the fact we can still bring one or two players in because we are still a little bit short."
Wenger, though, knocked down reports Arsenal were about to sign Shakhtar Donetsk's Brazilian midfielder Jadson, having last week denied a move for Juan Mata from Valencia.
"What I want to say is that we are not frightened to spend money, but we have to be convinced the player is better than what we have," the Arsenal boss said.
"That is our main concern, to bring quality. We have quality, but want to add more quality."
Nasri, meanwhile, labelled Arsenal fans as "disrespectful" after chanting against him at Newcastle on Saturday.
The 24-year-old did not feature at St James' Park because of illness, but was the subject of abuse from some sections of the travelling support, who questioned his loyalty and labelled him greedy.
Nasri, who is suspended for Tuesday night's Champions League play-off first leg against Udinese at Emirates Stadium, used his Twitter account to hit back.
He wrote: "I heard what the fans were singing about me on Saturday and it is really disrespectful because I'm still a (sic) arsenal player."