Tim Byrdak (knee surgery) wrote on his Twitter account Thursday that he will start playing catch Friday. Byrdak underwent surgery early last week to repair torn meniscus cartilage in his left knee. The veteran southpaw hopes to get back on a mound next week, but he's cutting things really close to be ready for Opening Day. Garrett Olson would likely take his place as the lefty specialist if he needs some extra recovery time.