Dec 4 (Reuters) - Manchester United ( MANU ) left back Luke Shaw said he has suffered another injury setback less than two weeks after returning to action.

The England defender has missed much of this year due to injuries and British media reported he had picked up another problem during training that may sideline him for weeks.

The 29-year-old, who missed the start of the season due to a calf injury, said in a social media post on Tuesday that he had had a small setback.

"I've been through a lot of ups and downs but this has definitely been my toughest period," he added. "I'm absolutely devastated and it's extremely tough to come to terms with reality at this moment in time."

Shaw, who was previously out for nearly four months with a muscle injury he picked up in February, came off the bench during United's 1-1 draw with Ipswich Town on Nov. 24 and made two more substitute appearances after that.

United, who are ninth in the Premier League, visit second-placed Arsenal later on Wednesday. (Reporting by Chiranjit Ojha in Bengaluru; Editing by Peter Rutherford )