Learn Italian: Se il capitano se la sentisse, sconfiggeremmo l'altra squadra. - If the captain felt up to it, we would defeat the other team.

Sentirsela is formed by combining the verb sentire (to feel) with the reflexive pronoun si and the direct object pronoun la. Whenever si is followed by another pronoun like la, it changes to se. Because the subject is il capitano (he), the third-person reflexive pronoun is si, which becomes se. So, we get se la before the verb.

Does the la in se la sentisse refer to a specific feminine noun like la squadra (the team)?

It doesn't have to! In pronominal verbs like sentirsela (to feel up to it) or prendersela (to take offense), the la is a fixed, invariable pronoun. It just represents a general concept of the situation or the task at hand, exactly like the word it in the English translation feel up to it.

Why is the verb sentisse used here instead of a normal past tense?

This sentence describes a hypothetical or unlikely condition. In Italian, when you use se (if) to introduce a hypothetical scenario, you must use the imperfect subjunctive for the if clause (se la sentisse) and the conditional tense for the result clause (sconfiggeremmo).

Why does sconfiggeremmo have a double m?