Who says the Tigers didn’t offer him a contract? Based on everything I have read, they did and he declined it.
Also, based on the salary committed to Valdez, it would be very hard to believe that the Tigers offered anything less to Skubal, and they almost certainly offered him something more. But Boras seems to have pegged Skubal’s value around 10/$400 million, which is a long way from the neighborhood that Detroit was probably playing in. If 10/$400 million is the price, I don’t want Detroit to pay it, especially having witnessed the last few years of Cabrera’s contract.