This sentence/paragraph is a mess. I think the writer meant "football is" rather than "football if," and there should be a comma after attrition. I'd put a period after cliche and start a new sentence, and I'd cut the last part of that sentence
By its nature, football is often a war of attrition, and coaches have turned the next-man-up mentality into a cliche. But they create problems that didn’t really need to exist.
FROM ANOTHER STORY: Howard has a lot of prove this upcoming season.
This writer did the same thing the above writer did; he/she used the wrong word. Obviously, he/she means to, not of.
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