If the St. Louis Cardinals are to sign free-agent right-hander Roy Oswalt, as reports suggest, then someone likely will need to be creative.

Maybe Oswalt, who could accept a discounted deal to play close to a farm that he owns in northern Missouri.

Or maybe the Cardinals, who could trade either right-hander Kyle Lohse or Jake Westbrook to clear a spot for Oswalt in their rotation.

Then again, maybe something else is going on — perhaps an undisclosed injury – that is creating a sudden need in St. Louis.

Oswalt prefers to play for the Cardinals or Texas Rangers, but was not close to a deal with the Cardinals late Friday night, major-league sources said.

Things change quickly in free-agent negotiations, as demonstrated by the Angels’ signing of free-agent first baseman Albert Pujols and Tigers’ signing of free-agent first baseman Prince Fielder. Club executives and player agents also leak inaccurate information on occasion to advance or disguise their own interests.

The Cardinals’ motives are unclear, but they have inquired about another free-agent right-hander, Edwin Jackson, in recent days, according to one source. They also made Oswalt a one-year offer of about $5 million earlier this month, the St. Louis Post-Dispatch reported. The Rangers, like the Cardinals, are interested in Oswalt but do not see him as an obvious fit. They have yet to make Oswalt an offer, a source said.

The Cardinals’ rotation already includes five veteran starters — right-handers Chris Carpenter and Adam Wainwright, lefty Jaime Garcia and Lohse and Westbrook.

Carpenter, 36, pitched a career-high 273-1/3 innings in 2011, including postseason. Wainwright missed all of last season after undergoing Tommy John surgery but is expected to be ready by spring training.

Both Lohse and Westbrook have full no-trade clauses and limited trade value. Both also would be rather expensive as relievers; Lohse will earn $11.875 million in 2012, Westbrook $8.5 million.

— Ken Rosenthal