Rumer Willis fights through rib injury during "DWTS" rehearsals

Rumer Willis and Val Chmerkovskiy on "Dancing with the Stars," season 20.

ABC

Battling for the top spot in the "Dancing with the Stars" finals won't be Rumer Willis' only tough fight this week.

The "DWTS" finalist suffered a rib injury last week while training with partner Val Chmerkovskiy for their Judge's Choice contemporary routine.

Their gorgeous "Swan Lake"-themed dance -- which the "DWTS" judges described as "beautiful," "a bit mad" and "brilliant dancing" and earned the couple a perfect score of 30 -- involved a ton of difficult lifts.

Unfortunately, all of the practice leading up to that intensive week nine routine badly strained Rumer's muscles, and her rib bones got extremely bruised.

Now, the partners are in overdrive rehearsing for two dances on Monday and a fusion dance on Tuesday, but it's very difficult for Rumer to practice. In an ET exclusive video, Val wants Rumer to see a doctor when the injury forces her to take a break during practice, but the 26-year-old actress insists, "I'm fine."

"I just need to catch my breath," she adds. "It's hard to take a deep breath, so I just need a second, and I'll be okay."

Ouch!

Rumer did say she felt good about the routine but wished "it wasn't so hard for me right now."

It's a bittersweet moment, especially when Rumer tears up explaining to Val, "I just don't want to let you down." Her dancing partner gives her a kiss on the head and insists that she won't.

How sweet is that?!

Luckily, Rumer has a ton of support. Not only is Val working hard to make sure they keep training safely, her mom Demi Moore, dad Bruce Willis and sistersTallulah and Scout Willis have all been cheering Rumer on.

The "DWTS" season 20 finals start on Monday on ABC. Riker Lynch and Noah Galloway are Rumer's big competition for the mirror ball trophy.

We hope Rumer feels better fast! Watch more on Willis here.