Benitez has been unable to win over a large majority of Chelsea supporters after he was appointed on a deal until the end of the current season following the sacking of the popular Roberto Di Matteo.
Results have been mixed since the former Liverpool boss took charge at Stamford Bridge, with Chelsea now 13 points behind current Barclays Premier League leaders Manchester United and facing a 2-0 deficit ahead of the second leg of their Capital One Cup semi-final with Swansea.
But, with Guardiola opting to move to German giants Bayern, Wilkins reckons Benitez could fancy himself to take the reins at Chelsea on a permanent basis.
The former England midfielder also defended Chelsea owner Roman Abramovich for the managerial turnover at Stamford Bridge since the Russian arrived in 2003.
"I think Pep going to Munich gives Rafa a chance, he will be thinking it (a permanent deal) is a possibility but it remains to be seen," Wilkins told Press Association Sport.
"Mr Abramovich has spent a lot of money and can do with the club what he wishes. Trophies have continued to roll in and they have been for the last 10 years so who is to say he is in the wrong with the way he does things?
"When you go into Chelsea you know exactly what you are getting into so don't be surprised. And when he has spent that amount of money, he is entitled to do as he wishes and if that means changing the manager once every year then that is his wish."
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Benitez was coy about his future following last night's 2-2 draw against Southampton, the Blues' third home game in succession without a win, with many supporters still unhappy with the Spaniard being in charge.
But Wilkins thinks a turnaround in form could soon win over the majority of fans.
"I think there is certainly a frosty environment within the ground," he said.
"But that is only down to the fact they aren't pulling those results together at the moment.
"I'm sure once those results start flying in it will completely different."
Abramovich has once again spent in the transfer market to secure the services of Demba Ba from Premier League rivals Newcastle.
Wilkins is a fan of Ba and thinks he could help Fernando Torres rediscover his form, even if he believes the Senegal international is just a short-term solution.
"He should have an impact on Fernando, he should raise his game a touch and want to impress," Wilkins said of Ba.
"He has got the position and has scored three goals already for them and is flying at the moment.
"It is a good buy but it is an interim buy I'd have to say because I think they will buy big in the summer - (Edinson) Cavani or Falcao seem to be the ones who are crossing people's lips."
Despite the 13-point margin between third-placed Chelsea and league leaders United, Wilkins is adamant Benitez will still be targeting the Premier League title.
But he feels the Red Devils' summer acquisition of Robin van Persie means the trophy will return to Old Trafford.
"Chelsea will go after Man City and they will go after Manchester United but, you would have to say, at the moment it is pretty much in the hands of Manchester United to throw away," he said.
"They look solid and they have a goalscoring machine in Robin van Persie and I think that signing will win them the Premier League."