The Browns signed Allen on Tuesday, Jeremy Fowler of ESPN.com reports.
Los Angeles has released Allen on Wednesday, Stu Jackson of the team's official site reports.
Allen (thumb) has been ruled out for Sunday's game against the Chiefs, Sarah Barshop of ESPN.com reports.
Allen (knee) is listed as out for Sunday's matchup against Dallas, Jourdan Rodrigue of The Athletic reports.
Allen (knee) has been ruled out for Monday's game against the 49ers, Gary Klein of the Los Angeles Times reports.
Allen will have a procedure on his knee and is expected to be sidelined 2-4 weeks, Stu Jackson of the Rams' official website reports.
Allen signed a three-year deal worth $24 million to remain with the Rams on Monday, Adam Schefter of ESPN reports.
Allen (knee) is active for Tuesday night's game against the Seahawks.
Allen (knee) is considered day-to-day after spraining his MCL in the Rams' win against the Jaguars Sunday according to head coach Sean McVay, Jourdan Rodrigue of The Athletic reports.