The phrase "to improve the team" means to make the group of people working together better, by enhancing their skills, effectiveness, cooperation, or overall performance. Full definition
We spent about # 85 Million last summer but we did not improve the team in any way or form. (justarsenal.com)
In every walk of life whether it's sporting or not, if you are not improving a team of people to produce better results consistently, you would quite simply be fired! (justarsenal.com)
Skilled at improving team performance through innovative management techniques. (livecareer.com)