The Chilean, who is out of contract at the Emirates Stadium next summer, was strongly linked with a deadline-day move to Manchester City.
It is understood that the Citizens were prepared to pay an initial £55m to sign the former Barcelona attacker, but Arsenal were unable to bring in AS Monaco's Thomas Lemar, which scuppered the deal.
Sanchez is reportedly 'devastated' that he failed to secure a move away from the Gunners last month, but Wenger has claimed that the club's star forward was 'never close' to leaving.
"It was not very close. It's very difficult for me to speak about that because what I want now is the player to focus on his career, on his season and on Arsenal football club," Wenger told beIN Sports.
"I cannot tell you everything that happened because after when you decide to let a player of that calibre go you need to replace him, because nobody would understand why you let the player go.
"And when you cannot do it you keep the player and make a financial sacrifice, because at the end of the day what you want is to have a team with a good potential and top quality."
Sanchez's first Arsenal appearance of the season came in last weekend's 4-0 defeat at Liverpool.