Carolina Panthers tight end Greg Olsen received an early birthday present Thursday. Olsen, who turns 30 next Wednesday, signed a contract extension that will keep him in Charlotte through 2018.According to his agent, Drew Rosenhaus, the three-year deal is worth $22.5 million with a hefty $12 million signing bonus.Olsen was one of 24 Panthers who entered the offseason with a contract that was set to expire after 2015. The final year of that five-year deal called for him to make a $5.25 million base salary, with a $7.8 million cap hit. Details of the Panthers’ potential savings against the cap after the extension were not immediately known.Carolina is also expected to extend linebacker Thomas Davis, whose contract is due to expire after 2015, sometime this offseason. The deals for defensive end Charles Johnson and center Ryan Kalil, which end after 2016, could be re-worked as well.Former Panthers general manager Marty Hurney traded Chicago a third-round pick for Olsen before the 2011 season. It turned into Hurney’s best trade while former Bears general manager Jerry Angelo has openly admitted he made a mistake.

Timeline: How Olsen Landed With the Panthers

After four seasons in Chicago, Olsen’s continued to get better during his four years in Charlotte, finally earning his first Pro Bowl appearance in 2014.