Counting the cats he had, the kittens he found, and the injured cat, Jeff had a total of 20 + 2 + 1 = <<20+2+1=23>>23 cats.
3 people took a total of 3 * 2 = <<3*2=6>>6 cats.
After Wednesday, Jeff was left with 23 - 6 = <<23-6=17>>17 cats.
#### 17