Daytona Beach, FL (SportsNetwork.com) - NASCAR handed down penalties to two crew chiefs in the Sprint Cup Series on Tuesday for technical violations discovered this past weekend at Las Vegas Motor Speedway.

Paul Wolfe, the crew chief for Brad Keselowski's No. 2 Team Penske Ford, was placed on probation through Dec. 31, and Steve Addington, the crew chief for Justin Allgaier's No. 51 HScott Motorsports Chevrolet, received a $25,000 for separate violations.

According to a news release from NASCAR, the right and left rear quarter panel wheel openings on Keselowski's No. 2 car were modified after qualifying inspection on Friday. The infraction is a P2 level penalty and violates the following sections in the 2015 NASCAR rule book:

12.1: Actions detrimental to stock car racing;

20.4.b: Body - All approved OEM-manufactured body components must be used as supplied except as required to stiffen, or to attach to other vehicle components. Tolerances from CAD surfaces and template tolerances are provided to allow for manufacturing, fabrication, and installation variability;

20.4.2: Surface Conformance - Coordinate measuring machines, scanning equipment, and templates, among other tools, will be used to inspect body surfaces for conformance to the approved OEM and NASCAR CAD files.

Allgaier's No. 51 car was found to be too light during post-race inspection on Sunday. The infraction is a P3 level penalty and violates the following sections:

12.1: Actions detrimental to stock car racing;

20.3.5: Added ballast containers:

a) Any and all ballast added to the vehicle must be bolted inside an added ballast container, inside the main frame rails, and/or inside the front sway bar.

b) Added ballast must be secured in a manner that will prevent movement of the ballast during an event.

20.17.2.2: Overall vehicle weight after competition:

b) After a vehicle has raced, only water in the radiator, oil in the engine reservoir tank, and fuel in the fuel cell may be added. Wheels and tires may not be changed, unless otherwise authorized by NASCAR Officials.

c) After a vehicle has raced, the minimum overall vehicle weight of all vehicles must be within 0.5% of the minimum overall vehicle weight required at the start of the race.

The ballast was observed falling off the No. 51 during the race, and the car did not meet post-race minimum weight requirements.