Detroit Lions running back Reggie Bush told reporters -- including Dave Birkett of Detroit Free Press -- that he is "optimistic" he'll be able to suit up Sunday despite his knee injury. While he has progressed throughout the week, Bush admitted that he has "some work cut out" before he's cleared to play."I'm always optimistic to be able to play," Bush said. "I hate missing games. It pains me to miss practice. I hate missing practice because I feel like the reps are vital to your performance on Sunday. Like I said, I'm optimistic to play Sunday, but there's so many different things that need to happen. I've got to get approval from the doctors and coaches and trainers, so I still have some work cut out for me."Bush suffered his knee injury midway through the second quarter when he took a helmet to his knee. He returned just before halftime but sat out for most of the rest of the game. He's considered day to day, and he's thankful that he avoided an injury that carries a more extended absence."I feel a lot better than I thought I was going to be feeling at this point in time," Bush said. "My knee feels pretty good. It's a day-to-day thing right now. Thankfully, I avoided anything serious that might have required surgery or being out for a long period of time."Bush didn't practice today for the second consecutive day. He's questionable to suit up this weekend, and the Lions showed against the Arizona Cardinals that they have a completely different offense without Bush in the backfield.If Bush is unable to go Sunday, the Lions will count on a combination of Joique Bell, Theo Riddick and Mikel Leshoure.Follow @TheNFLInjuryRpt Looking for fantasy football advice?