The agent is the person who sources out and receives opportunities and deals for the player. It is his job to secure, scour, speculate and broker sponsorships, endorsements, publicity or appearances for the player. The manager is the go-between person who okays these deals on behalf of the player and handles the business side of things. Thus, the manager is the person whom the player must trust the most because his/her judgment is the one that the player will rely on in their own best interest.
Example: Serena Williams' agent receives a call from Nike offering Serena a sizeable endorsement contract. If Serena is not directly available or is too busy, the agent will call Serena's manager to inform them of the offer and sell the idea to him/her. The manager will pass on this information to Serena and counsel her on the ramifications and possibilities that this deal may or may not have for her. Serena will then tell her manager whether or not she is interested in signing with Nike. The manager calls the agent back to tell them that Serena is interested/disinterested. The agent will then call Nike to set up an appointment to meet with Serena or decline their offer of a contract. In most cases, it would work this way. However, sometimes, the agent will speak directly to the player when it doesn't involve business, such as when Serena receives an invitation to attend a publicity party or a social engagement that involves her celebrity.
I'm not a sports agent, but i think this is how it works.
"There are more dogs than women in the locker rooms" - Liz Smylie
"I'm really feeling my balls" - Serena Williams
"She had him in her box... It made his week!" - Tracy Austin
"Tell us Rafa, what else do you do with your right hand?" - Todd Woodbridge
"I have a pain here, in my famous ass" - Rafael Nadal
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