First thing first, the head coach has to be the main leader for the team to be successful.
Past that, though, leaders have a different way for leading players. The leaders on a team don't always have to be the best players on the team, they can be the most respected, or just the most vocal.
Your Best Players
If your best players are going to be leaders, they have to show it every day. This type of leader needs to prove it to the team all the time. Sure, he may have a couple of games where he doesn't perform his best but everyone has those days. This type of leader is a great leader because he can teach the other players things because his skills are above the rest of the team. He can help the team like a coach, as long as the other players are willing to listen.
Your Most Respected Player
A respected leader is someone that just can be a great person or someone that everyone gets along with. This leader is a great leader on and off the field. He is a great role model for all the players. He helps the others on the team make the right decisions. He is the type of leader that if you see him working harder in practice you want to work just as hard too because he shouldn't do it by himself.
Your Most Vocal Player
A vocal leader can be good, when he is good at talking and getting the team pumped up right. He doesn't swear and doesn't talk too much. With this type of leader, it is hard to figure out the right mix. Sometime this leader doesn't have to talk much, but when he does everyone listens.
One thing all great leaders have in common is that they all can listen and follow directions. But, like I said, the coaches need to be the real leaders for the players. It is just that a coach isn't around the players as much as the other players. The coach need to find his leaders and talk to them about their roles.
Lastly, the leaders need to have a passion for the team if they are going to lead the team.