The Chilean striker continues to be linked with a summer move away from the Emirates Stadium with the likes of Chelsea, Manchester United, Manchester City, Juventus and Inter Milan all credited with an interest.
But manager Wenger is confident the 28-year-old, who is out of contract in the summer of 2018, will extend his time in North London once specific terms of a new deal are agreed upon.
"You amortise a transfer during the length of the contract," said Wenger.
"So when you play an amount of money, every year you deduct, when he signs four years, 25 per cent of a contract.
"The problem as well that you have to analyse, always, firstly, is: can you find better and for what kind of money? The inflation is so big that sometimes today even mathematically there can be advantages to keep a player until the end of a contract.
"But I personally think he will sign and stay here. First of all he is happy here. His desire is as well to stay. That is what I deeply believe. The disagreements are more purely contractual. Not on the desire. Both parties have the desire to find an agreement, so I think it will happen."
"I don't think that you would sell him to any Premier League club, that is for sure. Because you want to be as strong as you can be, and not strengthen the other teams.
"But I just told you that I think Alexis will stay here and sign a contract. You are in your job [in the media] where you are always painting the most dreadful situation. But we are not necessarily in that situation."