Ed Sheeran will perform a duet with Elton John during Sunday’s 55th GRAMMY Awards and he revealed how it all unfolded.

“I just got a call from him about two months ago just saying, ‘Yeah I’ve been trying to get you a slot playing on the GRAMMYs.’ I was like, ‘Okay, cool!’ Should be fun.”

While Ed’s no stranger to having duet partners he’s curious at how rehearsing with Elton will take place.

“I’ve dueted with a lot of musicians in the past. Rehearsing with them you just invite them around your house, have a cup of tea and a play,” he said. “How do you rehearse with Elton John? What do you do? He basically only plays one piano so it has to be his piano and I have to go to wherever that is.”

Nominated for Song of the Year for “The A Team,” Ed Sheeran is humbled yet realistic.

“It’s got some big competition there,” he told Y98/St. Louis.

The track is up against Miguel’s “Adorn,” Carly Rae Jepsen’s “Call Me Maybe,” Kelly Clarkson’s “Stronger (What Doesn’t Kill You)” and fun.’s “We Are Young” and he’s not betting on his own track. During a recent visit to St. Louis, Ed shared his pick for Song of the Year winner.

“I think fun. will win it. If you look at the situation I think fun. will,” Sheeran said. “Elton [John] thinks Carly Rae Jepsen will get it.”

Sheeran even told us how he would celebrate if he did win a GRAMMY.

“I’m thinking, if I don’t win, I’ll drink.”

He hopes that if he does win a GRAMMY, he’ll keep it together and be grateful rather than overly excited.

“If you win something like a GRAMMY, that has to be one of the biggest ego boosts ever. You’ll just be showing it to everyone.”

Does this mean Elton John also got Lady Gaga her spot on the 2010 GRAMMYs?

Watch Ed and Elton’s performance this Sunday, February 10 on CBS.

-Amy Determan, Y98/St. Louis