The U.S. women’s Olympic marathon team will be selected Sunday (April 20). The Olympic Team Trial is scheduled to begin at 8 a.m. in Boston, one day prior to the Boston Marathon.

U.S. marathon record-holder Deena Kastor, 34, is the favorite. Kastor set the U.S. mark while winning the London Marathon in 2006, with a time of 2:19:36. She was second in the U.S. Olympic Trials in 2004 and earned a bronze medal in Athens. The only other U.S. Olympic women’s marathon medalist, Joan (Benoit) Samuelson, won the initial Olympic marathon in 1984 and will also participate in Sunday’s Trials, though she is not among the favorites.

Colleen De Reuck, who won the 2004 Trials, will not compete Sunday due to injury.

The top three finishers Sunday will earn berths on the U.S. team, provided they have met – or will meet by July 23 – the Olympic qualifying standard time of 2:37.

More than 100 competitors will compete in Sunday’s Trials. Other performers to watch Sunday include the top five American finishers from the 2007 World Championships: Ann Alyanak, who finished 31st in Osaka, plus Zoila Gomez (35th), Dana Coons (38th), Mary Akor (42nd) and Samia Akbar (49th). Kastor competed in the 10,000-meter run at the World Championships, finishing sixth.

Sunday’s event will be webcast live on NBCSports.com/marathon, beginning at 8 a.m. MSNBC will broadcast a one-hour highlights show on April 27 beginning at noon.