SAN FRANCISCO -- Brendan Ryan began his Minor League rehabilitation assignment Sunday, but he got off to a bit of a rocky start.

Playing shortstop for Class A Palm Beach, Ryan went 1-for-5 with a throwing error, and he was picked off as well. Ryan did reach base on an error, so he was on base twice. The Palm Beach Cardinals were at home against Brevard County.

Ryan had been playing in extended Spring Training games, also at the Cardinals' Spring Training complex in Jupiter, Fla. By starting his Minor League rehab Sunday, he now has 20 days at most before he must be activated from the disabled list. Ryan has been sidelined since March 17 as a result of a muscle strain in his rib cage.

The Cardinals would like to see Ryan get into playing shape, but another element may play into their course of action with Ryan as well. There is some thought in the organization that he might benefit from getting at least a few games in chillier weather than he'll see in Florida, to see how the injury will respond to those conditions.