The midfielder will miss Arsenal's Champions League last 16 second-leg tie at Bayern Munich on Wednesday night, his club's Premier League visit to Swansea City on Saturday and England's World Cup qualifiers away to San Marino and Montenegro.
The midfielder returned in October from a 17-month absence because of a stress fracture to the right foot and Wenger said that the monthly scans on each foot had revealed bone bruising to the left. The manager said that it was the result of him over-compensating to protect the other foot and, although there was inflammation to the right one, it is not understood to be serious.
Wilshere's injury nightmare began when he suffered bone bruising to the right foot only to play on through the pain and make the problem worse. Both player and manager have been scarred by the experience and the very mention of bone bruising has been sufficient to trigger alarm, even if it has been detected in the other foot.
"Normally, if he did not have the history, you should say: 'Maybe he can go on,'" Wenger said. "But with the history we had last time ... [when] we said: 'OK, it's bone bruising, let him continue to play,' and it transformed into a stress fracture. That's why [this time] the specialist said we cannot take this gamble."
Wenger was asked whether Wilshere risked a stress fracture to the left foot if he continued to play without a rest. "Nobody knows," he replied. "It could. The other ankle transformed into [a fracture]. Would that happen on this side, we don't know."
Wilshere is recuperating in Dubai, he did not travel to Munich with the Arsenal squad on Tuesday and he is not scheduled to return to London until Friday, with Wenger reporting that he would not go straight into training.
Arsenal and the Football Association have had discussions about the situation, with the England manager, Roy Hodgson, forewarned and unlikely to include Wilshere in the squad that he announces on Thursday for the qualifiers. Hodgson is due to attend Arsenal's tie against Bayern, when they will attempt to make Champions League history by overturning a two-goal deficit in the away leg and he is disappointed to be deprived of Wilshere, with the Montenegro game appearing as pivotal to England's hopes of automatic qualification for the finals in Brazil next summer.
But Hodgson has a good relationship with Wenger and there is no sense that he will seek to make an issue out of Wilshere's unavailability. Wenger is hopeful that the player will be fit to return for Arsenal in the home match against Reading on 30 March, which follows the international break.
"England can see him, he can report to them, we have nothing to hide," Wenger said. "Jack is away now for a few days, he comes back on Friday and then, he still has no impact, no training. I cannot see him being available for England at all."
Wenger has played Wilshere in 26 games since his comeback against Queens Park Rangers on 27 October while Hodgson has used him in two England friendlies. Wenger has always been keen to protect Wilshere but he conceded that he might have been guilty of overplaying him.
"Maybe," he said. "I felt that in our last two games only [against Aston Villa and Tottenham Hotspur], he started to have to push. He's a winner. Once he's on the pitch, he keeps going but we are in a position as well where you need always your best players. It's difficult to say that you rest him when he feels [something] ... You ask him how do you feel? Perfect, he says. It's difficult.
"Maybe this is a good learning process for us ... maybe after 20 games, to give him a breather [of] one or two games and then he comes back. For us, it is not welcome but maybe for Jack, it is not too bad that he has a little breather. This is more about prevention."
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