Slot is where he will be drafted for. That probably puts him as a Day 2 prospect. That was the same thing said about Deebo Samuel as well but he went to a scheme with a creative OC which allowed him to get plenty of yards rushing as well as receiving.
2019 Chargers 2019 Colts
66.0 completion percentage 60.9 completion percentage
4,615 passing yards 2,942 passing yards
23 touchdowns 18 Touchdowns
20 interceptions 6 Interceptions
88.5 passer rating 88.0 Passer rating
38 years old 27 years old
These stats are basically identical. Rivers is not an upgrade. He has also stated that he does not want to mentor anyone.