Ritchie was reassigned to OHL Oshawa on Wednesday.
Ritchie scored a goal on five shots in Monday's 6-2 loss to the Islanders.
Ritchie signed a three-year, entry-level contract with Colorado on Monday.
Ritchie (shoulder) made his season debut for OHL Oshawa against Kingston on Sunday, recording a goal and an assist.
Ritchie (shoulder) will miss training camp and the start of the season, Ryan Boulding of NHL.com reports.
Ritchie underwent shoulder surgery following last season and didn't skate at Development Camp, Evan Rawal of Colorado Hockey Now reports.