Owen Coyle is certain new Chelsea boss Andre Villas-Boas will be a huge success at Stamford Bridge.[LNB] Although he enjoyed a stellar campaign with Porto last year, when he guided them to an easy league triumph and a notable Europa League success, Villas Boas remains a largely unknown figure to most Premier League fans.[LNB]However, it is a measure of how long the 33-year-old has been preparing for a coaching career that he took his pro-licence course at the same time as Coyle, who will celebrate his 45th birthday later this month.[LNB]And the Scot saw enough back then to know Villas-Boas was destined for the very top.[LNB]"Villas-Boas is a tremendous addition to the Premier League," said Coyle.[LNB]"I know him well. I did my pro-licence with him and really took to him.[LNB]"He is a fantastic manager, who has achieved such a lot at such a young age.[LNB]"He has so many attributes. He will be a great fit with Chelsea.[LNB]"There is no doubt he will be a huge success."[LNB]It was a busy day at Bolton on Monday, as Coyle unveiled new signing Darren Pratley and handed long-serving defender Ricardo Gardner a new one-year contract.[LNB]However, the former Burnley boss insisted there was no news on Gary Cahill, even though it is accepted by most Bolton fans that the England defender will be leaving the Reebok Stadium before the season begins next month.[LNB]"If someone comes in with the right deal for Gary and the club, he would go with our blessing," said the Trotters chief.[LNB]"He wants to play Champions League football and there has been unbelievable speculation regarding him.[LNB]"There have been elite clubs who have noted their interest. It is up to them to take that forward.[LNB]"They need to make a concrete bid so the club can look at it, otherwise there is nothing to talk about. That is the frustrating bit.[LNB]"We don't want to lose him. Until such time as we have an offer to consider, we must focus on Bolton."