The Reds' striker was excused from international duty for the Games after almost two full years of football due to his participation in the 2010 World Cup and the CONCACAF Gold Cup last year, during which he picked up the Golden Boot and Player of the Tournament awards as Mexico ran out as overall winners.
He was expected to join fellow Reds Tom Cleverley, Ryan Giggs (both Team GB), Rafael (Brazil) and David De Gea at the Games, but United and Mexico - who face Gabon, South Korea and Switzerland in the group stages - jointly decided it would be best for the 24-year-old to remain with the Reds to prepare for the new season.
While always passionate about representing his country, Hernandez admits he is pleased to be able to get a full pre-season under his belt and, despite his absence, he has high hopes for Mexico at London 2012.
"Of course, I always love playing for my country but the decision was made and I'm really happy to be able to work hard with United during pre-season," he told Inside United.
"I think Mexico have a real chance and a lot of good players. It’s a very good generation for our country. We won the Toulon Tournament [a prominent under-21 competition held in France every year], so there are a lot of hopes for the team.
"We know in Mexico football is a very popular sport, all the kids, all the people have high hopes for the team to compete for a medal. It’s a dream for all Mexicans and it’s a dream for all the boys that are playing. I wish them all the best."