The 31-year-old Urbina was the key player in the trade because Philadelphia needed an extra arm in the bullpen. Urbina, a two-time all-star, has a 1-3 record with a 2.63 ERA in 25 games. He had not allowed a run in his last 10 outings (10 innings) with six saves and 18 strikeouts in his last 15 innings.
"Urbina is a quality relief pitcher who gives us depth on a key part of our club," said Philadelphia General Manager Ed Wade. "He's pitched on a championship team and can pitch effectively in tight situations."
Detroit was 12-0 in Urbina's last 12 appearances.
Martinez, 32, can play every infield position. He is batting .268 in 19 games.
Polanco, like Martinez, is a utility player, was batting .316 in 43 games.