The former Preston North End centre back has travelled to Germany in order to have a hamstring complaint assessed and rectified
The Republic of Ireland international has been out of action since early October after hurting his hamstring during his side's 2-0 win over Bristol City.
According to a report in the Irish Examiner, St Ledger is currently in Munich having his injury assessed by a specialist, and there is a possibility that he may require surgery in order to rectify the issue.
Meanwhile, Stoke City midfielder Glenn Whelan has said that 'it would be great' if the Potters could get into European competition.
Tony Pulis' side currently sit in ninth position in the English Premier League and have enjoyed some favourable results recently, including a 0-0 draw away to Tottenham Hotspur on Saturday December 22.
"Results have gone for us, but there is still a long way to go until the end of the season," said Whelan. "It would be great if we could get into Europe through. Hopefully we will be there or thereabouts – we definitely want to kick on."