The One Where An Actress Was Almost Replaced.

Friends director James Burrows alleged that actress Helen Baxendale, who played Ross Geller (David Schwimmer)'s whirlwind romance Emily in season four and five, almost got removed from the show because she lacked a spark with her costar.

"Schwimmer had no one to bounce off," Burrows wrote in his memoir Directed By James Burrows, per People. "It was like clapping with one hand."

Burrows added that Baxendale was "nice, but not particularly funny" compared to Jennifer Aniston's Rachel Green, who famously had a will-they-won't-they relationship with Ross.

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

Nonetheless, Burrows, in spite of his creative hesitations, didn't take Baxendale off the show because of "tight" deadlines, according to the memoir.

"Often, you can't recast, because of tight shooting deadlines or other logistical considerations," said Burrows, who worked on the sitcom throughout the '90s. "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."

Moreover, Burrows acknowledged that, oftentimes, efforts are made to keep performers if the situation calls for it.

"If there's chemistry," he added, "the writers go to work to figure out some way of keeping the actor."

Friends co-creator Marta Kaufmann previously praised Baxendale's talents and admitted it would be hard to join the tight-knit cast.

"Helen came in and was brilliant," Kauffman told Entertainment Weekly in 1998. "It's a difficult thing we're asking her to do, because the audience is very resistant to that seventh person coming in. But you can see her being one of your friends."

At the time, the actress noted she had "ludicrous" luck to appear on the show.

Baxendale ultimately left Friends in season five when Emily and Ross called it quits after a tumultuous marriage. Since then, Baxendale has appeared Cold Feet, Cuckoo and Noughts + Crosses. E! News has reached out to her rep for comment on the memoir but hasn't heard back.

As for the rest of the Friends cast? Keep scrolling to see their best reunions over the years.

"Hi from the girls across the hall," Aniston wrote on Instagram on Jan. 12, 2020.

The Friends ladies reunited at the SAG-AFTRA Foundation's Patron of the Artists Awards in Beverly Hills in November 2019. Cox and Kudrow presented Aniston with one of two Artists Inspiration Awards.

Monica and Chandler reunited in November 2019!

Joey, Monica and Rachel reunited for a fun night in October 2019.

"Halfway there... #girlsnight #?" Kudrow wrote in June 2019, teasing fans about a possible reboot.

The Friends ladies get together for Cox's 55th birthday dinner in June 2019.

To help Courteney Cox promote her new show and Instagram, Ellen DeGeneres created a Friends set and invited Lisa Kudrow for a surprise appearance.

In December 2018, Cox supported her friend at premiere event for her Netflix movie Dumplin'.

Also in June 2018, the two attended the Chanel Dinner Celebrating Our Majestic Oceans benefit for NRDC Malibu.

In June 2018, the two attended the American Film Institute's 46th Life Achievement Award Gala Tribute to George Clooney.

In 2016, the two onscreen roommates reunited in London, baby! LeBlanc caught up with Perry backstage after the latter star's performance in his play The End Of Longing, which marked his playwriting debut.

Lisa Kudrow, David Schwimmer, Courteney Cox, Matt LeBlanc and Jennifer Aniston reunited for a 2016 NBC special dedicated to Friends director James Burrows. Matthew Perry was unable to attend as he was in London to star in his play The End of Longing. He did, however, appear in a videotaped message to introduce his former cast mates.

Kaley Cuoco  was overjoyed to get a picture with the cast. She wrote on Instagram, "Ummmm NIGHT MADE. Can't breathe #friends meets #bbt @bigbangtheory_cbs I died and went to heaven."

The two reunited at the 2016 WGA Awards,  appearing together onstage to present an award.

The two attended a screening of Just Before I Go, which Cox directed, in 2015.

The two attended the Phoenix House's 12th annual Triumph For Teens Awards gala in Beverly Hills in 2015.

In 2014, Cox joined Kudrow at a premiere event for season two of the HBO series The Comeback.

Also in 2014, the ladies of Friends reunited on Jimmy Kimmel Live!...

...where Aniston and Kudrow competed against each other.

In 2014, Perry returned the favor and guest-starred on Cox's show Cougar Town.

In 2013, Cox guest-starred on her Friends co-star's show Go On.

In 2010, Aniston guest-starred on the season two premiere of her Friends co-star's show Cougar Town.

For the latest breaking news updates, click here to download the E! News App