And Mourinho believes his Arsenal counterpart can have no excuses if they fail to land a first title in 11 years, given the amount of money Wenger has spent on new players.
The Blues manager has rarely seen eye to eye with Wenger and last season famously branded the Frenchman a “specialist in failure”.
He chose the week leading up to Sunday’s Community Shield clash between the two clubs to rekindle their war of words.
Wenger has delivered three Premier League titles since replacing Bruce Rioch as manager in 1996, but the Gunners have finished no higher than third in each of the last 10 seasons as the Frenchman often shunned big-money signings in favour of developing young talent.
Arsenal finished 13 points behind Chelsea last season as the Blues won the Premier League at a canter. But Mourinho believes the arrival in recent years of the likes of Mesut Ozil, Alexis Sanchez, Calum Chambers and Mathieu Debuchy for more than £100m means the Gunners are ready to challenge for league honours.
“If you add up the amounts clubs have spent in the last three or four years I think maybe you will find a surprise,” Mourinho, who allowed goalkeeper Petr Cech to join Arsenal in an £11million deal last month, said in the Guardian.
“If you put Ozil plus Alexis Sanchez, plus Chambers, plus Debuchy, you will find a surprise.
“It’s a fantastic squad with good players, fantastic goalkeeper, they are more than ready to be a title contenders.
“Get a calculator. That is the easiest thing, it leaves no space for speculation. If you want to be honest, objective and pragmatic it is the easiest job for a manager to do.”
Chelsea begin their title defence at home against Swansea on the opening day of the new Premier League season on Saturday, August 8.
Arsenal host West Ham at the Emirates Stadium a day later.