Cameroon midfielder Song has been linked with a £15million move to Barcelona.
When asked if the 24-year-old could leave and others come in, Wenger said: "Both can happen.
"This decision (on Song) is not made. No (bid has been made). I cannot tell you more."
The Arsenal manager added: "Midfield is a different area because we have nine or 10 midfielders of top-class quality.
"Just today we have six or seven midfielders available, plus (Jack) Wilshere and (Emmanuel) Frimpong who are coming back. (Abou) Diaby is available again, (Mikel) Arteta, (Santi) Cazorla, (Aaron) Ramsey, (Alex) Oxlade-Chamberlain now plays central midfield - this is an area we have much more freedom to make decisions."
Wenger confirmed central defender Thomas Vermaelen would be the club's new captain following Van Persie's departure. The Holland international is in the process of finalising the formalities of a £24million switch to Manchester United, having earlier in the summer announced he would not be signing a new deal with the Gunners.
Van Persie is the latest of Wenger's key men to move on, following last summer's departures of Cesc Fabregas and Samir Nasri.
However, the Arsenal manager is confident Belgian centre-back Vermaelen can lead the club forwards.
Speaking at this morning's press conference ahead of the Barclays Premier League opener against Sunderland, Wenger said: "Vermaelen was vice captain, so it is a quick decision.
"I think we have many potential captains, and Mikel Arteta will be the vice captain."
Wenger believes the summer additions of Olivier Giroud, Lukas Podolski and Spain midfielder Cazorla will go someway to offset Van Persie's departure.
"We have already invested the [Van Persie] money because we bought three players - we bought Cazorla, we bought Podolski and we bought Giroud," said Wenger.
"If needed we will invest more, but if you look at the number of players, we have a massive squad.
"We have plenty of players who have no chance to play at all.
"At the moment I believe we have what is needed to be ambitious and to play our game."
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"We regret that we have lost a great player and for one simple reason - he only had one year left on his contract. He wanted to go," Wenger said.
"We anticipated this situation might happen, therefore we bought Podolski and Giroud.
"I think we were prepared to keep him of course, but as well the worse (case scenario) was to sell him.
"Selling to a rival was not what we wanted, but there was not much choice.
"We had only one club really interested at the level we thought would be acceptable and that was Manchester United.
"At the end of the day, that was the only decision we could make."
While the manner of Van Persie's exit may not sit well with many Arsenal fans - following his carefully worded summer statement questioning the direction of the club which stood by him during injury-plagued spells on the sidelines - Wenger maintains it is now time for everyone to look to the future as he prepares for tomorrow's [Saturday] season opener against Sunderland.
"The reality is when the player doesn't want to stay you have two ways: you either force him to stay or you accept the reality and you let him go. I have chosen the second solution," said Wenger.
"I know it is a massive challenge and a massive gamble I took but we have the quality to deal with the problem we have, and at the end of the day I can talk and talk and talk but we can only show it on the pitch now.
"Time heals all things and of course at the moment people are hurt, which I understand, but what is important for us is to focus on the season in front of us.
"Players have gone, life goes on and the football club is 125 years old and other big players have left this club and we have always gone from season to season in a strong way."
While Wenger may not want to go on the record over his personal thought on the saga, there remains a sense of having been let down by the Dutchman, whom he brought to Arsenal as a raw talent in May 2004.
Publicly, though, the Gunners boss maintains people should remember what Van Persie contributed on the pitch, plundering 30 league goals last season to fire them into third place.
"We lose a great player, a world-class player, I don't deny that, it is a massive challenge to replace him, so we have to be even more of a team and work even more together to compensate that loss," he said.
"However, we have lost world-class players before and we always survived.
"Now it is down to performances on the pitch, how well we play.
"I believe in ourselves, I believe in our quality and spirit and we have to show that."