The contract will pay Ritchie $1.2 million this season and $1.4 million next season, and $2 million in 2020-21 for a total of $4.6 million, according to The Athletic's Eric Stephens.
Ritchie's contract holdout has seen him miss the club's first seven games of the 2018-19 campaign.
The 22-year-old is coming off his entry-level contract. In that time, he's tallied 26 goals and 59 points across three seasons. Last season, he put up 10 goals and 27 points in 76 contests.