What made Brown expendable is that the Rams needed to clear cap space for Fowler. They couldn't cut anyone who was on the roster opening day because their salaries were guaranteed at that point. If they had another option they likely would have kept Brown.
Fowler's 2018 salary was $3,638,21 . The Rams' share of that was $1,926,113. [overthecap.com]
"By releasing Brown, the Rams save $1.7 million this season, while taking on just $188,704 in dead money. The financial ramifications are likely the reason Brown was given his walking papers, freeing up space to fit Fowler under the cap." [theramswire.usatoday.com]
"The Rams elected to waive Brown on Tuesday to make room for Dante Fowler ..." [nfltraderumors.co]
"Brown’s release is relatively surprising because many fans thought he could fetch a late-round draft pick in a trade with the dire need of offensive lineman around the league. That seemingly was not the case as the Rams needed to create a roster spot for EDGE Dante Fowler Jr ..." [nfltraderumors.co]
"As a corresponding roster move after acquiring edge rusher Dante Fowler, the Rams have waived offensive lineman Jamon Brown." [www.therams.com]
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