C Phil Costa said physical concerns are the reason he decided to retire at age 26. Costa signed a two-year, $2.7 million contract with the Colts in March. He abruptly and surprisingly left that on the table by retiring Monday. "Unfortunately, the day-to-day physical rigor of the NFL season has taken a toll on my body and has been a driving force behind my decision," Costa said in a statement. He lasted only three games in each of the last two seasons, battling ankle woes.