المهاجم هيسدد على الجون.

In Egyptian Arabic, هـ here is a future marker. It turns يسدد into he will shoot.

• يسدد = he shoots / he is shooting
• هيسدد = he will shoot

A very common alternative spelling is with حـ instead of هـ, so you may also see حيسدد. Both represent the Egyptian future.

Because بـ and هـ/حـ do different jobs in Egyptian Arabic.

• بيسدد usually gives a present / habitual sense: he shoots, he is shooting, or he usually shoots, depending on context.
• هيسدد gives a future sense: he will shoot.

So in this sentence, the speaker is talking about an action that is about to happen, not one happening right now or habitually.

Because subject–verb order is very common and natural in Egyptian Arabic, especially in everyday speech and sports commentary.

So:

• المهاجم هيسدد = the striker will shoot

This sounds very normal in Egyptian. Arabic can also use verb-first order in other contexts, but this sentence is perfectly natural as it is.

الـ is the definite article, meaning the.

So:

• المهاجم = the attacker / the striker
• الجون = the goal

In a football context, this is very natural because the speaker usually means a specific player and the actual goal on the field.

Also, in Egyptian Arabic, الـ is usually pronounced more like el- or il-, not al-. So learners often hear:

• el-mohāgem
• el-gōn

Because سدد على is a very common football expression meaning to shoot at or to shoot on goal.

So it is best learned as a chunk:

• سدد على الجون = shoot at the goal

The preposition does not match English word-for-word. This is common when learning Arabic: the most natural preposition with a verb may be different from the one English uses.

الجون is a very common Egyptian football word meaning the goal. It is a colloquial sports term, and it is basically a borrowing from English goal.

In Egyptian speech, this is extremely normal. In more formal Arabic, you might see:

• المرمى = the goal / goalmouth
• sometimes الهدف in different contexts, though that can also mean a goal scored

So الجون is very natural in Egyptian colloquial, especially in football talk.

Because that is one of the most famous features of Egyptian Arabic: ج is usually pronounced as a hard g.

So:

• الجون sounds like el-gōn
• المهاجم sounds like el-mohāgem

This is different from Modern Standard Arabic, where many learners first meet ج with a j-like pronunciation.

A natural pronunciation would be approximately:

el-mohāgem hayisaddid ʿal-gōn

A few useful notes:

• المهاجم → el-mohāgem
• هيسدد → hayisaddid
• على الجون is often said quickly as ʿal-gōn

So in fast speech, the whole sentence flows together quite smoothly.

A more formal equivalent would be something like:

سيسدد المهاجم على المرمى

Main differences:

• Egyptian هيسدد becomes formal سيسدد
• Egyptian الجون becomes formal المرمى
• Egyptian often prefers more colloquial vocabulary and pronunciation

So the sentence you were given is clearly Egyptian colloquial, especially because of هـ for the future and الجون for goal.