The former Arsenal forward also believes injuries have so far stopped him from reaching his potential.
Following an expletive laden chant about rivals Tottenham Hotspur during Arsenal’s trophy parade of the FA Cup, the FA recently charged the midfielder with misconduct.
It is the latest in a number of minor issues the England man has been involved in over the years, with smoking having been a big issue last summer and Nicholas says he must learn from his mistakes and mature.
“He just needs to mature a bit,” he said.
“I do believe he’s got the right mentality – he’s certainly got the capabilities – to be at Arsenal for some time, but he’s got to understand these things and he will learn.”
The former forward also believes that the midfielder is yet to reach his potential but can still be a top player for the Gunners.
Wilshere has suffered a series on ankle injuries since breaking onto the scene, with many at the time regarding him as not only one of Arsenal’s brightest hopes, but England’s too.
Those injuries have curtailed that somewhat for him though, with him now fighting for a place in Arsenal’s star-studded and on-form midfield and though Nicholas says the injuries are only part of his failure to fulfil his potential.
“Jack has gone through a pretty testing time over the past two years,” he added.
“He hasn’t fulfilled his potential yet and part of that is because of his injuries. But Jack’s a young, strong man and he’s still fighting – plus he’s never complained about the situation.”