Three days after a conference call with Packers team officials in which quarterback Brett Favre vehemently expressed his desire to play in 2008, on Friday Favre officially asked by letter for his unconditional contractual release, a source close to Favre and the team said. Favre, expressed a desire to have an friendly parting, as the Packers have been hesitant to embrace his return. Favre has three years left on his contract at a total of $39 million. He currently is on the reserve-retired list.

Seven-time Pro Bowl defensive end Michael Strahan is retiring after a 15-year career, capped by a Super Bowl title with the New York Giants in February. He holds the NFL record for sacks in a single season with 22.5, breaking New York Jets great Mark Gastineau’s total of 22 in the 2001 season. Strahan retires with 141.5 career sacks, 794 career tackles, 4 career interceptions, 21 forced fumbles and 2 career touchdowns in 200 games over a 15 year career (through 2007 season).

Trevor Linden ended his NHL playing career Wednesday as the Vancouver Canucks‘ second-leading scorer and one of the more popular players in franchise history. He is the Canucks’ all-time leader in assists (415) and games played (1,140) and is just behind Markus Naslund in goals (318) and points (733).

“It’s been fantastic for me,” Linden said at a news conference Wednesday. “I’ve been able to be a professional athlete for 20 years. It’s the right time.”

Linden totalled 375 goals and 492 assists for 867 points in 1,382 NHL games with the Washington Capitals, Montreal Canadiens, New York Islanders and Canucks, who drafted Linden second overall in 1988. He is expected to leave the game for a period to concentrate on a current real-estate project in Victoria.

A source has told The Associated Press that Detroit Red Wings goaltender Dominik Hasek is expected to announce his retirement from the NHL. The Red Wings have scheduled a press conference for Monday for today. Over the course of 16 NHL seasons, Hasek posted a record of 389-223-82, with 81 shutouts and a career goals against average of 2.20. At 43, he is the NHL’s oldest active goalie.

Hasek has won six Vezina Trophies as the NHL’s top goaltender, two Hart Trophies as the league’s most valuable player and an Olympic gold medal with the Czech Republic at the 1998 Nagano Olympics.

Hasek leaves the game after a rough and cut short run to his second Stanley Cup this season. He lost his starting role in Game 4 of Detroit’s first-round series against the Nashville Predators to Chris Osgood, who remained the starter during the team’s run for the Stanley Cup.

Mike Piazza, 39, who hit more home runs than any other catcher in history, announced his retirement Tuesday after no team was willing to sign him and offer significant playing time. Piazza now may be eligible for the Hall of Fame in the same class as Barry Bonds and Sammy Sosa and pitcher Roger Clemens.

“I knew this day was coming, and over the last two years, I started to make my peace with it,” Piazza said in a statement. “It has been an amazing journey. … I walk away with no regrets.”

Piazza was a 62nd-round draft pick by the Los Angeles Dodgers in 1988 who turned into a 12-time All-Star. He hit 396 of his 427 homers as a catcher during his 16-year career. He was willing to sign with a club that would provide playing time in at least half the games as a catcher or DH but received no offer, agent Dan Lozano said.

Brett Favre - The Green Bay quarterback never took a game off during his 16 years with Packers and became the face of the franchise, setting myriad of records, most notably for most career NFL touchdown passes (442), most career NFL passing yards (61,655) and most consecutive starts among NFL quarterbacks (253).

Bobby Knight - With an astonishing record of 902-371, The General is currently the all-time winningest Division-I head coach and is best known for his time with Indiana, where he led the Hoosiers to three NCAA titles.

Steve McNair - As a former co-MVP, Steve McNair had given his body to the game. After last season, though, the barrel-chested slinger declared: ”Physically, I couldn’t do it anymore.”

Larry Allen - The 11-time Pro Bowler and long-time Dallas Cowboy retired as a San Francisco 49er. Allen is considered a first-ballot Hall of Famer.

Annika Sorenstam - The 37-year-old Swede, who has won 10 majors, 72 Tour events and $22,081,561 overall, announced Tuesday that she would step away from the LPGA Tour at season’s end.

Vinny Testaverde - A great symbol of longevity, Vinny Testaverde, 44, threw for more than 46,000 yards and holds the NFL record for having thrown a touchdown pass in 21 consecutive seasons.

Monica Seles - Tennis fans can bid a formal adieu to the winner of 53 singles titles. She captured eight of her nine major championships by the age of 19. Not even a stabbing by a crazed fan in 1993 could end her career as she returned to the game 27 months later.

Pat Riley - On the heels of a 15-67 season, the former director of the Lakers Showtime teams stepped down as coach of the Heat with an NBA championship ring for each finger.

Chris Webber - Known best for his flash as the leader of Michigan’s Fab Five, the No. 1 pick in the 1993 draft retired after a series of knee injuries limited his movement and effectiveness.

Dale Jarrett - Back in October, the three-time Daytona 500 winner and the 1999 Cup Champion announced that he will drive off into the sunset after 24 years.

Mike Rucker - One of the most beloved Carolina Panthers, the defensive end retires as the second-leading tackler and sacks leader in team history. His only Pro Bowl selection came during the Panthers 2003 Super Bowl season, when he had a career-high 12 sacks.