SCOTTSDALE, Ariz. -- The Brewers expect to get an idea of the severity of Braden Looper's rib-cage injury Monday, when the right-hander visits a doctor in Phoenix.

Looper was scratched minutes before his scheduled Brewers debut Saturday when he felt a tweak on the left side of his lower back during pregame warmups. He did participate in some plyometric throwing drills Sunday morning.

"He felt the same as yesterday. There was no change today," general manager Doug Melvin said. "We just have to wait a few days to see. It's early enough in the spring to wait and see, monitor it, manage it and get more information."

Manager Ken Macha was concerned that the longer Looper is unable to pitch, the longer his absence will become. That's because if he goes a significant stretch between starts, he may have to start from scratch with bullpen sessions and live batting practice to rebuild his arm for another stint in a game.

As Macha explained it, "it's almost like the multiplication tables."

Looper's uncertain situation already has minor implications for pitching coach Bill Castro. The Brewers have a "B" game scheduled for Monday morning in Glendale, Ariz., against the Dodgers, and suddenly have enough pitching for only five innings. Chris Narveson and Cody Scarpetta will work in that game.

Because the Brewers are a bit short of arms, the teams may play the first five innings as usual before the Brewers bat until the Dodgers have exhausted their supply of pitchers in need of work.