How do you upgrade skill points in madden 11 superstar?

In Madden 11's Superstar mode, you can upgrade skill points by earning experience through gameplay. As you perform well in games—completing passes, making tackles, or achieving other objectives—you'll accumulate experience points. Once you have enough experience, you can access the "Upgrade" menu to allocate skill points to various attributes for your player. Focus on upgrading skills that align with your player's position and play style for optimal performance.