Twitter can be both a gift and a curse for professional athletes. On the one hand, it gives them the ability to interact with their fans on a regular basis. But on the other, it lets anyone in the world @ them with nasty messages, trash talk, and, in some instances, death threats. Chargers running back Ryan Mathews found that out the hard way recently. He says that several fans contacted him on Twitter with a particularly mean-spirited message.

"I've had people say they hope me and my mom gets AIDS and die," he revealed earlier this week.

Why? He says that it's because he hasn't lived up to all of the hype that he received after the Chargers selected him No. 12 overall in the 2010 NFL Draft.

"So far, what I've done right now, I've been just an average back," he said. "I got a lot of people just frustrated with my performance in the last few years. They expected me to come in and do big things."

Fair enough. But still, wishing AIDS on a player (and his mom!) because of his performance on the football field? Not cool, San Diego. Not cool at all.

RELATED: The 100 Biggest Twitter Fails in Sports History

[via NFL]