Could you teach me the grammatical structure and meaning of the following sentence?
It's an excerpt from the article attached.

"a big reason why is star third..."

This sentence is on the second line in the first paragraph.
I'm guessing that it was made by inverting the sentence
'why third baseman Evan Longoria is star'.

Am I correct?

See a translation

The Tampa Bay Rays are perennial contenders in the American League East, and a big reason why is star third baseman Evan Longoria.

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broken up into pieces:

1. "The Tampa Bay Rays are perennial contenders in the American League East."

perennial contenders:
they are often in a position to win the championship.

2. "and a big reason why is star third baseman Evan Longoria."

and a big reason why is ---> Evan Longoria

also can be written as
'and a big reason why: Evan Longoria, whom is star third baseman.'



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another way of writing it:

The Tampa Bay Rays are continuously doing very well in the American League East. A big reason why this is happening is because of Evan Longoria, star third baseman.