Rotate 1 frame of a spritesheet

I have a spritesheet that contains frames for an animation. The issue is that some of the frames are rotated 90 degrees. If I import the spritesheet and slice it inside of unity, the animation builds fine, but the handful of frames are rotated. I dont have the source animations and would prefer to not have to break out the sprite sheets and reassemble them in photoshop so all frames have the same orientation

Any ideas? Im thinking I could trigger an event in the animation, then rotate the whole thing, but that sounds very messy

Any ideas?

Thank you!