Who plays the most important role in a sales team ?

No role is less important than the other. The word 'team' is used indicating talent infusion! From top down to bottom up, everyone plays a huge part in a sale! 

Team leader plays a major role in sales team. Team leader is the captain of the ship. A good team leader of a sales team can make or break a company.  Without a strong leadership the revenue that pays employee wages can vanish.

Team Leader Palys a very important role in sales 

Everyone in the sales team.

In a team, every role has got its own importance and the task can not be completed without every team members involvement. That is the reason why it is a team work rather than an individual work. In my opinion all roles are important.

You said Sales TEAM ! and you can't devide a team. All are important in sales. we don't also forget the after sales team ;)

In all kinds of teams (in sport or profession) the “win-defining score” determines the key players or excellent scorers!

(In football or cricket, the best players mostly overshadow the team manager or trainer in publicity, right?)

While all teams need team spirit & collective work to achieve well, the manager (in sport or profession) is the one charged with forming, building, coaching & adapting the team to achieve desired “scoring results”. He or she can actually attain key-players or produce excellent payers (salespersons) through training & coaching (whether in house or external).

So, my vote goes to the sales manager as he is the one with more authority to form, build, coach, evaluate, adapt in order to improve others. Not the other way around.Having said this, without excellent team-members a manager's position would have no meaning or function (unless a one-man business)

THE PERSON WHO IS IN DIRECT INTERACTIONS WITH THE ULTIMATE CONSUMER 

Leader who can guide individulals what to sell and where to, with answers to team queries about product, pricing and future support.

Everyone's role is important in a way. It's a team effort.