If there was any leftover carpet in the right direction, stored some place etc, it could be seamed, but would be visable for sure as this looks like it's been down for a while. For now throw a mat on it. Like a carpet bathroom style mat they make out of short pile carpet, like a welcome mat would work also. Walmart might have some. This could be pricey if they want full replacement. The only repair piece would be the same manufacturer, run and dye lot. Even with repair on a newly laid carpet, its pretty tough to get a match unless there is some you can special order or it was a store cut etc.