[Grammar] Punctuation

[Lemon]

Although Mr. Ryan will be unable to attend this week's event he, along with all of the district managers from the east coast, will be at the one next week.

I found this paragraph online and I think there should be a comma between 'this week's event' and 'he'.
Is it possible to write the paragraph without another comma after 'this week's event'? If one more comma is needed, could you explain why? Thanks in advance.

 

[emsr2d2]

You're right that another comma is needed. If we remove the whole bit about the other managers, you'll see why.

Although Mr Ryan will be unable to attend this week's event, he will be at the one next week.

Including the extra information doesn't remove the need for that comma.