Johnson, a former professional wrestler, plays a football player who learns he has a daughter. Sedgwick's character is a demanding agent who cares nothing about the little girl, played by Madison Pettis, The Hollywood Reporter said.
Johnson ruptured an Achilles tendon in June, delaying production, which is now scheduled to start Sept. 24, The Reporter said.
Nichole Millard and Kathryn Price wrote the script for "The Game Plan," which is being produced by Mark Ciardi and Gordon Gray -- who also produced the current Disney football hit "Invincible."
"Kyra will add a great comedic touch to the film, and we're glad to have her on board along with the Rock's newly healed Achilles," Gray said.