Simplify the following text for a Grade 6 native English-speaking person.
Original: Mariano Rivera ( born November 29 , 1969 ) is a Panamanian right-handed baseball pitcher who has spent his entire 17-year Major League Baseball ( MLB ) career with the New York Yankees .
Simplified: Mariano Rivera ( born November 29 , 1969 in Panama City , Panama ) is a baseball player . He has played with the New York Yankees for many seasons .