Giovani dos Santos
Giovani dos Santos has already struck three goals for Mexico in the London Olympics. Reuters

When and where: The men's Olympic soccer Semifinal kicks-off from Wembley Stadium at noon ET. Coverage will be provided by the NBC Sports Network, with a live stream available on NBCOlympics.com.

Preview: Mexico and Japan meet in the Olympic semifinals on Tuesday after progressing past the last round in very different manners. While Mexico were considered one of the pre-tournament medal contenders, such has been the ease of their progress that it is Japan who may start as slight favorites.

Since a shock opening 1-0 victory over Spain, the Japanese side have not looked back, keeping a clean sheet in each of their four matches. Last time out they comfortably dispatched an Egyptian side hamstrung by being reduced to 10 men after 41 minutes. By that stage Japan were already a goal to the good, however, and never looked like relinquishing their advantage before adding two goals late on.

Mexico also progressed to the knockout phase without the loss of a goal. In contrast, though, Mexico's quarterfinal with Senegal was packed with drama. After sweeping into a two-goal lead, Luis Fernando Tena's side conceded twice in 10 minutes to take the contest into extra time. Mexico were left thanking some further slack defending by their opponents as they struck twice to eventually end Senegal's resistance.

Despite relinquishing a strong lead, Tena said that he was taking the positives out of his side's performance.

"What makes me happiest is the fighting spirit of our team, because we were leveled on the scoreboard and raised (our spirit) very well," Tena said, according to the Press Association. "(It was) nothing to be depressed or anything, instead it was when we started playing better."

Certainly Tena should know all about his side's opponents in the semifinal. The two teams met in a pre-Olympic friendly last month when Japan came out on top 2-1. With so much more at stake in this rematch, though, little can be read into that result.

Giovani dos Santos was absent from that clash, but will be expected to again be a talisman for El Tri as he has been for much of the competition. The performance of talented 23-year-old Marco Fabian will also be important, while Hector Herrera may return in midfield after scoring off the bench against Senegal.

Japan have plenty of quality of their own to keep a close eye on. Forwards Yuki Otsu and Kensuke Nagai have each scored twice and will be hungry for more to take their side into the gold medal match.

Neither Japan or Mexico have reached the final of the Olympics, with the closest they have come being when both lost in the semifinals in the Mexico City Games of 1968. When the two faced off for bronze, it was Japan who came out on top, 2-0.

Prediction: This match is almost too close to call and could well be decided by the finest of margins. Japan's defensive record speaks volumes and Mexico will have to attack with real vigor to get a breakthrough. For their part, Mexico's defense will have to avoid the kind of lapses that allowed Senegal a way back in their quarterfinal.

While it may not repeat the goal-scoring drama of yesterday's women's semifinal between the United States and Canada, Mexico and Japan could go equally as far into the match, and perhaps longer, before a winner emerges.

Mexico 1-1 Japan