Lewis returns to screens later this week as he bumps into old flame Audrey Roberts (Sue Nicholls) at a country pub. He later shocks everyone by turning up in Weatherfield, claiming that he is a changed man and wants to make amends for his past misdeeds.
However, Havers told itv.com that he is unsure whether Lewis will manage to win back Audrey - and whether he really can be trusted to stay on the straight and narrow.
The 62-year-old explained: "Lewis does a runner after first meeting Audrey, because he's so scared of what's going to happen. And then, he thinks to himself, 'Hang on - I better pull myself together'. He turns up in Coronation Street and, quite courageously, says, 'Bring it on. Come on, go for me'. Which they do!
"He says that it was implanted in his DNA to behave like that, he's thought long and hard about his behaviour, he's now a changed man, he's come back to get his just desserts and he's going to be a different human being from now on.
"Audrey may or may not believe Lewis's new side. We have to wait and see. Even I don't know!"
Discussing the troubles ahead, Havers continued: "He has Deirdre to see - I'm not looking forward to that. Lewis is heading for a very rocky comeback. Watch this space."
Havers also said that he was delighted when Coronation Street bosses told him they wanted him back.
He said: "It feels wonderful to be back in Coronation Street. I had such a good time last time - a year and a half ago, I was last here. What an honour to be asked back."
Coronation Street airs Lewis's return scenes on Friday, February 17 at 8.30pm on ITV1.
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