Do professional soccer/futbol athletes learn to fake injuries so they can penalize the other team?

Absolutely- they flop worse than basketball players. As soon as the yellow or red card comes out, they spring back to their feet like nothing happened. An injury that requires that much time to get back up should disqualify a player from returning. If it's genuine, they wouldn't return anyway. If they're faking, which they are 90% of the time, they should be penalized for it.