The injured middle finger on Ben Sheets' pitching hand will have to improve dramatically over the next couple of days for the Milwaukee Brewers' ace to take his next scheduled turn Thursday against Arizona. Sheets, who exited his start Saturday night in the fourth inning after spraining the top joint on the finger, was wearing a compression wrap on the damaged digit Sunday. He said he was still unable to put any pressure on the finger while holding a baseball. "That's what hurts - pressure one way," Sheets said. "When I couldn't put pressure on the ball (Saturday night), that's when I stepped off the rubber." X-rays showed no fracture in the finger, but Sheets will undergo a magnetic resonance imaging examination today to assure there is no other damage.