Tired from practice, AND Spending too much time preparing for a match
Participial phrases are verb phrases that act as adjectives to describe nouns. Putting these participial phrases into a sentence makes it easier to see how this works. Tired from practice, Justin decided to take a nap before doing his homework. In this sentence, "tired from practice" describes Justin. Spending too much time preparing for a match, Justin felt unprepared for his Calculus test. "Spending too much time preparing for a match" also describes Justin.
The sentence used the word "will" which indicates that the action is "not done yet" and just about to be done. Therefore it is an example of future tense.