New York Mets starter Johan Santana, hobbled by a sore back, is done for the season, club General Manager Sandy Alderson said Wednesday. Santana went on the 15-day disabled list with inflammation in his back. Alderson said rookie right-hander Collin McHugh will take Santana\'s place in the Mets\' rotation, MLB.com reported. Santana, in his first season back from left anterior capsule shoulder surgery, experienced back stiffness following a bullpen session this week. A magnetic resonance imaging test revealed damage, which prompted the Mets to shut the left-hander down, MLB.com said. Santana, a 33-year-old, two-time Cy Young winner, was 6-9 with a 4.85 earned run average in 21 starts this season. He threw a no-hitter June 1 against St. Louis, but had not won since June 30 at Los Angeles.