Final answer:
The underlined phrase in the sentence is a prepositional phrase that indicates the location.
Step-by-step explanation:
The underlined phrase in the sentence is a prepositional phrase. It functions as an adverbial phrase modifying the verb 'made' and answers the question 'where?'. The prepositional phrase in this sentence is 'on and outside the fields', indicating the location where the players picked up the tennis balls.
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