You might try just pinning it where you want to sew or basting it in to see how it looks. The only thing I'd be afraid of is, after sewing, it would be too bulky in the seam and some sweaters unknit themselves if you cut the fabric. I've bought sweaters that were too big in the wrist and I put a hem in the bottom of the sleeve and run a narrow elastic in it to just gather it up. I do that most of the time. I am short and have a very hard time finding long sleeves that don't come past my fingertips. :-D :-D