Elton John's royal wedding performance will likely include a tribute to Princess Diana (Exclusive)

Prince Harry and Meghan Markle are pulling out all the stops for their star-studded big day!

A source tells ET that Elton John, a friend of Harry and Prince William's late mother, Princess Diana, is set to perform at the royal wedding reception, and it's sure to tug at everyone's heartstrings.

"It is no surprise that Elton has been included in Prince Harry's wedding. As one of Diana's closest confidantes, Elton is a connection to Harry's mother and a very supportive friend," the source says of the music legend. "The plan is for Elton to play at the wedding reception has been in place for a while."

Adds the source, "The wedding itself will be very formal and the reception is meant to be more fun, and that is where Elton comes in."

In 1997, John reworked his 1973 song, "Candle in the Wind," which was originally a tribute to Marilyn Monroe, in honor of Princess Diana. It is thought that the 71-year-old musician will also honor Harry's mother on Saturday.

"He plans to sing and there's also been talk of some type of tribute to Diana, one in which Elton will speak at the wedding and say how much she is missed on this very special day," the source notes. "[Elton] has remained very close to her sons."

As for what the "Rocket Man" singer things of Meghan, the source continues, "Elton thoroughly approves of Meghan and feels they are a perfect couple and very in love. Elton thinks Diana would be proud and would love Meghan."

The final details for Saturday's nuptials are coming together. Kensington Palace confirmed Friday that Prince Charles, Harry's father and Diana's ex-husband, will walk Meghan down the aisle. This comes after Meghan announced on Thursday that her father, Thomas Markle, would not be attending following heart surgery.

Prince Philip's attendance at the ceremony — which was uncertain following hip replacement surgery last month — was also confirmed by Buckingham Palace on Friday.

Watch the video to see how Meghan and Harry plan to pay tribute to Diana, and keep up with all of ET's coverage of the royal wedding as we count down to the big day!

Reporting by Adriane Schwartz.


Meghan Markle and Prince Harry's Pals Priyanka Chopra and Elton John Brag About the Couple

Prince Charles Will Walk Meghan Markle Down the Aisle at Royal Wedding

John Legend Tweets Sympathy for Meghan Markle Amid Royal Wedding Family Drama