"Friends" director James Burrows writes in his new memoir that producers nearly recast Ross' wife Emily, played by Helen Baxendale.

In his new memoir "Directed By James Burrows," he writes that Baxendale's chemistry with Schwimmer didn't always generate big laughs.

"Schwimmer had no one to bounce off," he wrote. "It was like clapping with one hand."

He continued, "In sitcoms and any type of romantic comedy, the funny is just as important as the chemistry. We discovered that any new girlfriend for Ross needed to be as funny as Rachel."

Rachel was played by Jennifer Aniston.

Recasting Emily became difficult because of the show's tight deadlines.

"Often, you can't recast, because of tight shooting deadlines or other logistical considerations," Burrows wrote. "You need someone who gets laughs. Sometimes you start an arc and it ain't working out, so you have to get rid of that person. If it's a day player, it's a quick goodbye."

Baxendale had a fairly long run on the show. Her character Emily was introduced in Season 4 and appeared in 14 episodes in all. Emily and Ross married in Season 5, but Ross said Rachel's name during the vows by accident.

When Emily and Ross broke up, Baxendale was written off the show.