I will suggest downhearted or dispirited because they are disheartened and unwilling to fight for the same end. A successful teamwork need a great communication, a good spirit and positive energy to reach the goal. Retrieved from: http://constructingexcellence.org.uk/resources/teamworking/

I will suggest downhearted or dispirited because they are disheartened and unwilling to fight for the same end. Successful teamwork needs great communication, a good spirit and positive energy to reach the goal, as suggested on this page about teamwork by a UK consulting group.