Red Sox might be a taker for Cubs' Marlon Byrd

ST. LOUIS – Keep an eye on the Boston Red Sox’ developing outfield situation. The Cubs are.

Depending on how they view the prognosis of center fielder Jacoby Ellsbury’s shoulder injury, the Red Sox could turn to the Cubs, who have been willing to trade center fielder Marlon Byrd for months.

That could open another avenue in the Cubs’ ongoing efforts to strengthen their bullpen.

Although it might take a week or more before the Red Sox determine whether they’ll look outside for help, insiders suggest the Cubs’ front office, which maintains close ties to several Red Sox officials, is monitoring the situation.

Early reports from Boston say Ellsbury could miss at least four to six weeks with a partially dislocated right shoulder suffered Friday. The Red Sox called up defensive-minded prospect Che-Hsuan Lin, but they admit that he’s short-term protection in the field.

‘‘It’s safe to say Lin is not on the roster as a solution if Jacoby is out for a long time,” Red Sox manager Bobby Valentine told reporters Saturday, ‘‘but stranger things have happened.”

Cubs general manager Jed Hoyer declined comment when asked about the potential for talks with the Red Sox.

What’s certain for now is that the Cubs continue to look for ways to acquire pitching, particularly proven, durable relief pitching, after losing some of their biggest arms over the winter in trades (Andrew Cashner, Sean Marshall) and role changes (Jeff Samardzija).

‘‘We worked to acquire starting pitching depth over the course of the winter, but we traded out of the bullpen,” Hoyer said, ‘‘so replenishing that depth is something we’re going to be looking to do throughout the summer.”

La Russa influence

Cubs manager Dale Sveum played part of one season for Tony La Russa 19 years ago with the Oakland Athletics, but he said he learned a lot from the recently retired White Sox/A’s/Cardinals manager.

He might even try La Russa’s often-debated practice of batting his pitcher eighth.

‘‘I’m not going to say I wouldn’t,” Sveum said. ‘‘There’s situations where you would. It’s usually when you can get two leadoff guys [back-to-back]. That’s when it works best.”

Notes

Starlin Castro entered Saturday leading the National League in stolen bases (six, without getting caught). Through nine games, the Cubs are 8-for-10 on steal attempts. Their total through nine games last year: zero on two attempts.

â—† Already without Lance Berkman (calf) for the series, the Cardinals scratched David Freese (finger) on Saturday.

â—† Jon Jay’s two-out home run in the seventh off Shawn Camp snapped the Cubs bullpen’s scoreless-innings streak at 91/3. It dated to Tuesday and included 11 strikeouts.