Aston Villa captain Stiliyan Petrov has been diagnosed with acute leukemia, the Premier League club announced Friday.

Petrov's illness was discovered in medical tests carried out on the 32-year-old Bulgarian international after he came down with a fever following last Saturday's defeat at Arsenal, the club said.

Reigning champ Novak Djokovic beat a stubborn 21st-seeded Juan Monaco 6-0, 7-6 (7/5) Friday to book a re-match of the 2009 Miami Masters final with Scotland's Andy Murray.

Murray, who got the better of Djokovic in the 2009 title match, reached the final on a walkover when world No. 2 Rafael Nadal pulled out of their semi-final with a sore left knee.

A 10-man medical commission will meet Monday to determine if Italy forward Antonio Cassano can begin playing again following minor heart surgery.

Cassano's club AC Milan announced that it asked the Italian Sports Medicine Federation to gather a panel of experts to analyze the striker's condition.

Arsenal coach Arsene Wenger got a three-match touchline ban from UEFA on Friday for comments directed at the referee after his team's Champions League elimination this month.

UEFA said its disciplinary panel found Wenger guilty of "improper conduct," and fined him €40,000 ($53,000).

Manchester City will be without star striker Sergio Aguero for the Premier League clash against Sunderland with a "stupid" injury, club manager Roberto Mancini confirmed Friday.

Aguero was missing from the City team that drew at Stoke on Saturday with a foot problem.

World number one Novak Djokovic booked a semi-final showdown with Juan Monaco at the Miami Masters by holding off a determined David Ferrer of Spain 6-2, 7-6 (7/1).

"It's always going to tough against David, he's one of the greatest competitors on the circuit," said Serbia's Djokovic, winner of the last three Grand Slams. "I didn't want to get to the third set because physically he's always there."

Three-time runner-up Maria Sharapova booked her second straight Miami final Thursday, rallying to beat disgruntled Caroline Wozniacki and set up a title clash with Agnieszka Radwanska.

Sharapova clinched a 4-6, 6-2, 6-4 semi-final victory over the Dane after two hours, 34 minutes, the match ending in acrimony as Wozniacki objected to the chair umpire's overrule of a call to Sharapova's benefit on match point.

Brazil coach Mano Menezes says he has doubts over whether Kaka can force his way into the 2014 World Cup team, putting the onus on the Real Madrid player to prove he is worthy of a spot.

Menezes told Brazilian channel SporTV on Thursday that he thinks Kaka could be key for Brazil in the World Cup, but said "next season will tell if Kaka can still play for Brazil in a World Cup. We all have doubts."

The Miami Heat shrugged off back-to-back road defeats to post a decisive 106-85 victory against the Dallas Mavericks, the team that beat them in last season's NBA championship series.

The Heat, with their star trio of LeBron James, Dwyane Wade, and Chris Bosh leading a balanced attack, surged to a 13-point lead in the third quarter, adding another victory over the Mavericks to the win they posted in Dallas when the lockout-shortened season opened on Christmas Day.

Diego Maradona was restrained by security staff as he confronted opposition fans in the stands on Thursday, angry at threats and abuse directed toward wives and girlfriends of his al-Wasl players.

Maradona called the al-Shabab fans "cowards" after they heckled the women during his team's 2-0 loss.