Miami Dolphins running back Knowshon Moreno isn't off to a good start with his new football team.

Moreno is going to undergo arthroscopic surgery on his left knee.

He'll be out four to five weeks. That means he could miss the start of training camp and possibly the first preseason game or two.

Moreno was signed to a one-year, $3 million contract this spring.

However, he hasn't been able to practice much this spring and Lamar Miller is the returning starter.

Moreno is a former Denver Broncos starter.

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Aaron Wilson covers the Ravens for The Baltimore Sun