The general rule is that for every 1,000 feet of elevation your sustained aerobic capacity - crucial in a sport such as soccer - diminishes by about 1%.
Probably little or no effect IMO
Altitudes of all 10 stadiahttp://tinyurl.com/3ydwxnxAnd from this articlehttp://tinyurl.com/363kfcdcomes the interesting quoteThe general rule is that for every 1,000 feet of elevation your sustained aerobic capacity - crucial in a sport such as socc