Here's why Prince Harry and Meghan Markle had sleepless nights before baseball game

Though the Duke and Duchess of Sussex Prince Harry and Mehan Markle might have put on a big smile at the baseball game between the New York Yankees and Boston Red Sox in London, they were running lack of sleep.

According to People, the 34-year-old Duke of Sussex revealed that he and his wife pulled the entire night trying to make their 7-week-old son Archie sleep.

After posing for pictures before Saturday's game, they attended a reception where they met athletes of the Invictus Games, an organization he founded in 2014 for injured servicemen and women that was a charity partner at Saturday's London Series.

During the event, the royal couple met Bianca Rainbow-Jones and her 9-month old daughter, Raphaella, to support her husband, Nathan Jones, an Air Force service member.

Rainbow-Jones on talking about the conversation she had with the couple said, "We talked babies! They said, 'We've just left [the screaming] - we had that about an hour before we came here!' ".

Adding, she went on to say, "Harry said they had a sleepless night."

The 37-year-old Duchess of Sussex surprised fans by making an unannounced appearance at the first-ever regular season MLB game, which took place just weeks after she welcomed son Archie on May 6.

The new mom wore a black Stella McCartney dress with a colour-coordinated belt for the outing. Wearing a similarly-hued outfit, Harry proudly wore a black Invictus Games polo with a pair of dark pants.

Although the royal parents were seen without their little bundle of joy, they did receive adorable outfits for the little one from both teams, including a Yankees jersey with his name printed on it.

The couple's made their first visit to London's former Olympic stadium almost after nine years when Harry first took place in a baseball game, throwing the ceremonial first pitch at a New York Mets game in 2010.