Colts owner Jim Irsay says his team must be prepared to start the season without injured quarterback Peyton Manning. Irsay posted his comments Saturday morning on his Twitter account, less than 12 hours after the Colts lost their eighth straight preseason game. "We r evaluating the QB sitch,#18 healing but we got 2 b prepared 4 early season possibility without him,defense has 2 pick it up,big time!" Irsay wrote. During a conference call with reporters, coach Jim Caldwell was asked when he expected Manning to be back. Caldwell hasn't provided a timeline for Manning's return and says he hasn't been cleared to practice. "Bottom line, we truly do not know when he will be ready," Colts president Bill Polian said. "Once the nerves regenerate properly, he'll be ready. When that happens, he'll be ready to ramp up immediately. It's impossible to predict."