The US singer has reportedly been spotted backstage at the music festival in Pilton, Somerset, after arriving on site on Thursday (23 June).
There are whispers doing the rounds that she will team up with recent collaborator Mark Ronson for a DJ set in the Shangri-La area on Saturday night.
A source told The Sun she was spotted milling around behind the Pyramid Stage, revealing: “She was clocked by a few people but she kept a low profile.
However, if she does play the set, she faces a race against time to return to the States for a rather important prior engagement.
“Mark is playing officially in the early hours of Sunday morning but they are trying to make another set work because she is due back in the States to meet the Dalai Llama on Sunday,” the festival insider added.
Lady Gaga previously played Glastonbury in 2009, when she performed on the Other Stage.
No doubt she will be supporting close friend Adele at this year's festival, with the superstar set to headline the Pyramid Stage tonight.
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