Serena Williams returns to tennis court

Serena Williams grabbed her racket and got out on a tennis court Tuesday, which she said was her “first day back” after a series of health problems, including blood clots in her lung.

The 13-time Grand Slam singles champion and former No. 1-ranked player has not played an official match since she won the title at Wimbledon in July.

Shortly after claiming her fourth singles championship at the All England Club last year, Williams cut her foot on glass at a restaurant, an injury that led to two operations. The second surgery was in October, and she said she spent 10 weeks in a cast and 10 weeks in a walking boot.

The 29-year-old American was diagnosed in February with blood clots in her lung. After that, she said she needed treatment for a hematoma — a gathering of blood under the skin — on her stomach.

Williams has not said when she might return to competition.

Roger Federer started his clay-court season Tuesday by dispatching Philipp Kohlschreiber of Germany, 6-2, 6-1, with precise shot-making at the Monte Carlo Masters.

In other matches, Ivan Ljubicic defeated Jo-Wilfried Tsonga of France, 7-6 (2), 6-4, and Milos Raonic downed Ernests Gulbis, 6-4, 7-5. Tomas Berdych defeated Olivier Rochus, 6-2, 6-3, to set up a match against Ljubicic.

Barcelona, Manchester United advance to Champions League semifinals

Lionel Messi scored his record 48th goal of the season Tuesday to give Barcelona a 1-0 victory over Shakhtar Donetsk of Ukraine as the Spanish club advanced to the semifinals of soccer’s European Champions League for the fourth successive season.

Barcelona, a three-time European champion, had won the first leg of the quarterfinal series, 5-1, at home and took the series, 6-1 on aggregate, after the win in Donetsk.

Manchester United, another three-time champion, also reached the semifinals by completing a 3-1 aggregate win over Chelsea. Goals by Mexico’s Javier Hernandez and South Korea’s Park Ji-Sung gave Manchester a 2-1 win in Manchester, where Didier Drogba scored Chelsea’s lone goal. Manchester had won the first game, 1-0, in London on a Wayne Rooney goal.

The quarterfinals conclude Wednesday with home games for Tottenham Hotspur, which trails nine-time champion Real Madrid, 4-0, and Schalke ’04 of Germany, which leads defending European champion Inter Milan, 5-2.

— Grahame L. Jones

Attorneys for NFL players meet with magistrate

Attorneys for NFL players met in Minneapolis with the federal magistrate who will oversee court-ordered mediation with the league as the lockout reached one month and counting.

Attorneys and Hall of Fame defensive end Carl Eller sat down with U.S. Magistrate Judge Arthur Boylan in a session that lasted well into the afternoon. All declined to comment. The NFL’s attorneys are scheduled to meet with Boylan on Wednesday before mediation begins on Thursday.

UCLA’s Lee, Nelson, Honeycutt share MVP honors

Junior Malcolm Lee and sophomores Reeves Nelson and Tyler Honeycutt were selected co-most valuable players during UCLA’s awards banquet at the Hyatt Regency Century Plaza. All three players were first team All-Pacific 10 Conference selections.

— Ben Bolch

Florida basketball Coach Billy Donovan said assistant Richard Pitino is leaving to become the head coach in waiting at Louisville.

Donovan said Pitino, son of Louisville Coach Rick Pitino, will be named associate head coach for the Cardinals. Rick Pitino declined comment on his son’s status.

Butler shooting guard Shelvin Mack said he is declaring to enter the NBA draft but has not hired an agent, making him eligible to return to school next season.

Former Utah basketball standout Will Clyburn is transferring to Iowa State.

The 6-foot-7 swingman told the Associated Press that he plans to sign a financial aid agreement with Iowa State in the coming days. Clyburn will have to sit out next season under NCAA transfer rules, and he’ll be eligible for only the 2012-13 season.

Clyburn led the Utes in scoring and rebounding last season, averaging 17.1 points and 7.8 rebounds. He spent his first two years at Marshalltown Community College, a short drive east of the Iowa State campus in Ames.

Clyburn and former Michigan State guard Korie Lucious will both play their final seasons for the Cyclones in 2012-13.

Dallas Stars fire Marc Crawford

The Dallas Stars fired coach Marc Crawford after missing the playoffs in each of his two seasons. Crawford won the 1996 Stanley Cup with Colorado, and later coached in Vancouver and Los Angeles.

Jack Capuano is sticking around as coach of the New York Islanders, losing the interim tag Tuesday after guiding the team to a much-improved second half of the season.

The Phoenix Coyotes have recalled defensemen Oliver Ekman-Larsson and Nolan Yonkman from the minors as they get ready to open their first-round NHL Western Conference playoff series Wednesday at Detroit.

The Edmonton Oilers will pick first overall in the NHL draft for a second straight year.

The New Jersey Devils won the draft lottery Tuesday, but teams can’t move up more than four spots, leaving Edmonton with the first overall pick.

The Devils will pick fourth, the New York Islanders fifth and the Ottawa Senators were bumped down to the sixth spot, with Colorado and Florida falling in order at second and third, respectively.

The NHL draft is scheduled for June 24-25 in St. Paul, Minn.

The Portland Trail Blazers have signed center Earl Barron for the rest of the season. Barron has played parts of five seasons with Miami, New York, Phoenix and Milwaukee. He has averaged 5.2 points and 3.6 rebounds, appearing in 108 games, including 27 starts.

The New Orleans Hornets’ team doctor said star forward David West had successful surgery to repair a torn ligament in his left knee and is expected to recover fully.

The San Diego Sports Commission has confirmed that Michigan State and North Carolina will play in the Carrier Classic on Veterans Day, Nov. 11. It will be the first NCAA basketball game to be played aboard an aircraft carrier.

The commission said approval from the Navy is expected soon.