The Miami Dolphins' defense took an early hit in Sunday's season-opening loss to the Las Vegas Raiders.

Rookie linebacker/defensive back Kyle Louis suffered an MCL sprain and is expected to miss a few weeks, according to ESPN/NFL Network's Ian Rapoport. The fourth-round pick exited early Sunday with the knee injury, cutting short his highly anticipated NFL debut.

It's disappointing timing for both Louis and a Miami defense that could desperately use his skill set. Louis didn't get much of an opportunity to make an impact against Las Vegas because of the injury. Now, instead of building momentum early in his rookie season, he'll have to focus on getting healthy before establishing himself as a consistent piece of the defense.

Miami needs him back as soon as possible.

The Dolphins aren't expected to overwhelm many opponents defensively this season, which puts even more pressure on Malik Willis and the offense. Willis, De'Von Achane and Miami's young receiving corps give the Dolphins enough playmakers to remain competitive, but the defense has to give them a chance.

That didn't happen against the Raiders. Las Vegas scored 27 points in Miami's 27-13 loss, forcing the Dolphins to play from behind and putting additional pressure on an offense still finding its identity with Willis under center.

It's only one game, and Miami has plenty of time to figure things out. The same goes for Louis.

An injury in the opening game of a rookie season is about as frustrating a start as possible, but the good news is that Louis isn't expected to be sidelined long-term.

Once healthy, the Dolphins will hope their versatile rookie can provide exactly the spark this defense needs.