his eyes wander. he usually talks to ALL THE FEMALES. he's shady, even when it seems like he likes you (you can just sense you're not the only girl his attention is on). if he flirts or flatters you a lot, chances are he flirts and flatters every other chick. he has a bad reputation/sleeps around. you catch him in a lie all the time. or he cheated on his last girlfriend.
Ask if you can look at his phone. If he says no for any reason he's probably a pla<x>yer. If he is use him abuse him and then set him free. Before he does it to you.<br />
Arrogance and a lack of depth are usually pretty good signs. If he's a pla<x>yer, drop him and don't fuel his already-large ego.
He might wear a jersey, or carry around a ba<x>seball bat, a football, but it depends on which sport he plays.
A pla<x>yer does not really have much time for you. His communications are infrequent and short. His avowals of love don't bear out in his other behaviour. Contrast this with a man who wants to commit to you: he responds promptly to your communications. You have no doubt about how important you are to him. You are central in his world and you feel like it could last for ever. You know he only has eyes for you.
Not letting you see his cell phone.
If you think he constantly lies, he's a pla<x>yer (or cheat). My grandfather taught me when I was younger, a liar is a cheat and a cheat is a liar. - Lies are a huge red flag, if you catch him in one... integrity is questioned.
another sign is he's very jealous - a thief thinks everyone steals and a player thinks everyone cheats
i tried to live with a cheating femme-fatale once, and she taught me quite a lot
He's on a playing card.
He has rewards card around his neck, and if he is ask him to share the comps.