Answer:
...The soccer team had a great staff consisting of Coach Smith, the head coach; Mr. Trent, the assistant coach; and Ms. Barton, the athletic trainer.
Step-by-step explanation:
Why? In this sentence, the semicolon is used to separate the three items in the list: Coach Smith, Mr. Trent, and Ms. Barton. Each of these items is a phrase that includes a comma, so the semicolon is used to clearly indicate where one item ends and the next begins.