Nasz zawodnik dobrze broni, ale rzadko strzela bramki.

Because nasz has to agree with the noun it describes.

• zawodnik is masculine singular
• so the possessive adjective is nasz

Polish adjectives and possessive words change form to match the noun’s gender, number, and case.

Compare:

• nasz zawodnik = our male player
• nasza zawodniczka = our female player
• nasi zawodnicy = our players

Zawodnik is a broad word meaning competitor, athlete, or player, depending on context.

In this sentence, because we have defends well and rarely scores goals, the natural translation is player.

So nasz zawodnik means something like:

• our player
• or more literally, our athlete/competitor

Broni is the 3rd person singular present tense form of bronić.

So:

• ja bronię = I defend
• ty bronisz = you defend
• on/ona broni = he/she defends

In the sentence, it matches nasz zawodnik, which is a singular subject.

Because dobrze is an adverb, and it modifies the verb broni.

• dobry = good, as an adjective describing a noun
• dobrze = well, as an adverb describing an action

So:

• dobry zawodnik = a good player
• dobrze broni = defends well

English works the same way here: we say he defends well, not he defends good.

Because Polish present tense is commonly used for habitual, regular, or general actions.

So dobrze broni, ale rzadko strzela bramki does not mean only right now at this moment. It can mean:

• he generally defends well
• he tends to defend well
• he rarely scores goals in general

This is very normal in Polish, just as in English:

• He defends well but rarely scores goals.

Rzadko means rarely and it modifies the verb strzela.

Its placement here is natural and neutral:

• ale rzadko strzela bramki = but he rarely scores goals

Polish word order is more flexible than English, but this version sounds very standard.

You may also hear other orders for emphasis, but this one is the safest pattern for learners.

Because Polish often omits subject pronouns when the verb form already makes the subject clear.

In English, you must say:

• he defends
• he rarely scores

In Polish, the verb ending often tells you the person and number, so on is often unnecessary:

• dobrze broni
• rzadko strzela

Here the subject is already established by nasz zawodnik, so repeating on would usually be unnecessary.

Yes, literally it is something like shoots goals, but idiomatically it means scores goals.

In Polish sports language, strzelać bramki is a normal expression.

This is different from:

• strzelać do bramki = to shoot at the goal

So:

• strzela bramki = scores goals
• strzela do bramki = shoots toward the goal

That is an important distinction.

Because bramki is the accusative plural of bramka here, used as the direct object of strzela.

The base noun is:

• bramka = goal

Plural:

• bramki = goals

In this case, the accusative plural has the same form as the nominative plural, so you still see bramki.

A learner may expect the form to change more visibly, but for many feminine nouns, it looks the same here.

Yes, gole is also very natural in sports Polish.

You can hear both:

• strzela bramki
• strzela gole

Both mean scores goals.

Very roughly:

• bramki may feel a bit more literally tied to the idea of goals
• gole is also very common, especially in football contexts

So the sentence is perfectly natural, but it is not the only possible wording.

Yes. Both bronić and strzelać are imperfective here, and that matters.

Imperfective verbs are used for:

• repeated actions
• habitual actions
• ongoing actions
• general characteristics

That fits this sentence perfectly, because it describes what kind of player he is in general:

• he defends well
• he rarely scores

A perfective verb would not fit as naturally here, because the sentence is not about one completed event.

Yes, very possibly.

Because of dobrze broni and rzadko strzela bramki, many readers would imagine a defensive player or especially a goalkeeper, since goalkeepers defend and rarely score.

Still, grammatically the sentence itself does not force that interpretation completely. It could also describe any player whose main strength is defending rather than scoring.

Only the noun phrase at the start would need to change:

• Nasza zawodniczka dobrze broni, ale rzadko strzela bramki.

Changes:

• nasz → nasza
• zawodnik → zawodniczka

The verbs broni and strzela stay the same in the present tense, because Polish 3rd person singular present forms do not change between he and she.