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After maintaining he was the "Happy One" during his Chelsea return, Jose Mourinho's combative side is back on display.

Arsenal manager Arsene Wenger called Mourinho's repeated attempts to downplay Chelsea's Premier League title prospects a "fear to fail." At a news conference later Friday, Mourinho snapped back: "He is a specialist in failure. I'm not."

Wenger, who has been in charge at Arsenal since 1996, has not won a trophy since the 2005 FA Cup.

Mourinho called himself the "Special One" at the start of his first spell with Chelsea, which ran from 2004-07, and he led the Blues to their first two English league titles since 1955. Before returning to the west London club last June, Mourinho won the Champions League with Inter Milan and the Spanish league with Real Madrid.

"If supposedly (Wenger) is right and I'm afraid to fail, it's because I haven't failed many times," Mourinho said. "Maybe he's right. Maybe I'm not used to failing. The reality is he is a specialist.

"Eight years without a piece of silverware, that's failure ... if I don't win a trophy in four years, I don't want a new contract, even if the club wants to give me (one). It's as simple as that."

Chelsea leads the Premier League with 12 matches remaining, one point ahead of Arsenal.

"If we don't win a title in one year, is that a failure? Or if we don't win a title in two years, is that a failure?" Mourinho said. "I have lots of respect for (Wenger) and I thin'k he is a great manager. But when he speaks about failure ... failure is not winning a title in seven or eight years."