The value of the vertical jump is that it show's a player's ability to burst off the line of scrimmage with lower body strength. That's why the drill is important for linebackers and defensive linemen despite the fact that they, in theory, are not jumping around much trying to defend passes.
Wrist tendonitis, also called tenosynovitis, is a common condition characterized by irritation and inflammation of the tendons around the wrist joint. Many tendons surround the wrist joint. Wrist tendonitis usually affects one of the tendons, but it may also involve two or more.
However, if you have actual joint redness or swelling, arthritis might be a possibility, and you would need to see your doctor about that right away. Tendonitis in the wrist is very common, and it produces exactly the kinds of symptoms that you are experiencing.