Wenger is set to celebrate the milestone achievement against rivals Chelsea at Stamford Bridge on Saturday, 18 years after arriving in England.
The Frenchman joined Arsenal from Japanese outfit Nagoya Grampus in 1996, replacing Bruce Rioch, and he has since guided the club to 11 trophies, including four Premier League titles.
However, it has been slim pickings for Arsenal in recent times, having gone nine years without silverware.
Wenger has come in for heavy criticism in the midst of Arsenal's trophy drought but Winterburn leapt to the defence of the 64-year-old manager.
"If you look at it in black and white and say, over this period of time where they haven't won anything, is he lucky to be in the job? A lot of people will say yes he is but I look at it slightly differently," Winterburn said.
"I look at the manager I worked for. I look at what's happened at the football club. How things have changed.
"We're coming in a period now which is far more important for Arsene Wenger than maybe the last three, four or even five years because they lost their big players.
"If you lose (Robin) van Persie, you lose (Samir) Nasri, who was playing very well at the time, you lose (Cesc) Fabregas. The players that came in didn't match those players.
"But now, I think we've seen a role reversal with (Mesut) Ozil coming into the football club I think people are starting to think, it looks as if Arsenal are going to start re-strengthening that squad again."
