Dallas Mavericks still missing crucial piece even after signing Klay Thompson

The Dallas Mavericks made one of the biggest moves in franchise history earlier this week when they made a sign-and-trade for Klay Thompson.

Dallas had been looking to improve their shooting, and they did so by adding one of the greatest shooters of all time in Thompson. A day before Dallas signed Thompson, they made a different move to sign Naji Marshall.

Dallas' No. 1 priority of the offseason was originally to sign Derrick Jones Jr., but after Jones Jr. switched agents at an unideal time, Dallas shifted their focus to signing Marshall and pursuing a sign-a-trade for Thompson.

Dallas Mavericks need an elite point-of-attack defender badly

Even after Dallas' move for Thompson, the Mavericks still have a huge hole on their roster, especially with Jones Jr. signing with the Clippers.

The Mavs don't have an elite point-of-attack defender like they had in Jones Jr., and considering they only have one open roster spot and not much cap space, it's going to be hard for them to address this need.

Sure, they have Quentin Grimes who they acquired in the Tim Hardaway Jr. trade, and he is expected to help their defense out, but the Mavs don't have a defensive stopper like they had with Jones Jr. at the point of attack. At one point, Thompson was an elite defender, but a couple of injuries later, he is no longer that same defender.

The problem with the Mavs lacking an elite point-of-attack defender hasn't been talked about much, and this issue could grow if they don't find a way to land an elite perimeter defender with the remaining cap space they have.

There's no question that the Mavs got better this offseason, and adding Thompson to this already-stacked Mavs roster is going to help them tremendously, but losing Jones Jr.'s lockdown defense is going to hurt them.

The Mavs could consider signing someone like Dennis Smith Jr. due to his elite defense, and he may just be the missing piece to help Dallas make another deep playoff run. He is elite at the point of attack, and although his offensive game is limited, his defense would make up for it.

The Mavs likely won't be able to find a defender as good as Jones Jr. on the free agency market right now, but adding defense with this last roster spot will be important.

For all the latest on Klay Thompson and the Dallas Mavericks all offseason long, stay tuned.