The Chargers said in a statement they presented Bosa with an offer on Tuesday night that included:
an initial signing bonus payment that is larger than any rookie has received in the last two NFL drafts,
and the "largest payment and the highest percentage of signing bonus received in the first calendar" of any Chargers first-round pick since the adoption of the NFL's collective bargaining agreement in 2011.
The Chargers said Bosa rejected the offer on Wednesday.
"The offer that we extended was for Joey to contribute during all 16 games and beyond. Joey's ability to contribute for an entire rookie season has now been jeopardized by the valuable time he has missed with his coaches and his teammates," the team said in the statement.
"Since Joey will not report at this time, his ability to produce not just early in the season, but throughout the entire season, has been negatively impacted.
"As a result, we will restructure our offer since Joey will be unable to contribute for the full 16 game season without the adequate time on the practice field, in the classroom, and in preseason games."