At Old Trafford: At the home of Manchester United FC, the U.S. women's soccer team plays old rival Canada in the semifinals. A victory and it's on to Wembley Stadium and a chance to win a third consecutive gold medal on Thursday. The Americans are 4-0 with shutouts in the last three. France plays Japan in the other semifinal.At North Greenwich Arena: Two more gymnastics medals are up for grabs for the U.S. in the individual apparatus finals. Gabby Douglas, the women's all-around gold medalist, goes for her third gold on the uneven bars, and Sam Mikulak will compete in the men's vault final.At Olympic Stadium: Defending champion LaShawn Merritt's quest for a medal in the 400 meters ended Saturday with a hamstring injury halfway through his heat, dashing the U.S. hopes for a seventh consecutive gold in the event. No American advanced to today's final. Kirani James, 19, a former track standout at Alabama, can formally break the U.S. winning streak and become the first medalist from Grenada. Angelo Taylor tries to pass Edwin Moses and Glenn Davis to win three golds in the men's 400-meter hurdles. In women's pole vault, Jennifer Suhr of the U.S., the silver medalist in Beijing, and two-time defending Olympic champion Yelena Isinbayeva of Russia renew their rivalry. Becky Holliday of the U.S. also qualified for the finals. In women's shot put, former Longhorn Michelle Carter and Jill Camarena-Williams try to give Team USA its first medal in more than 50 years.At the Basketball Arena: The U.S. men, who rallied past Lithuania on Saturday to remain unbeaten, face a threat from 3-1 Argentina in the final pool play game. Argentina won gold in 2004 at Athens and won bronze in 2008 at Beijing. It features a trio of NBA players -- Manu Ginobili, Luis Scola and Carlos Delfino . Carmelo Anthony leads Team USA in scoring with 20.5 ppg. The medal round begins with the quarterfinals on Wednesday.