Dreger noted that the deal would likely feature an average annual value (AAV) in the range of $3.25 million to $3.5 million.
This comes after Dreger reported the Leafs had unsuccessfully attempted to get a deal done in February. Dreger noted in April that the club offered a pair of contracts, a two-year deal with a $2.1 million AAV and a four-year pact with a $2.6 million AAV, around the trade deadline.
In his first full season in the NHL, the 24-year-old Johnsson recorded 43 points (20 goals, 23 assists) in 73 games with a plus-minus of 14. His 20 goals were tied for fifth on the team. Meanwhile, he tallied one goal and three assists in seven postseason games.
The news of an impending extension comes after Toronto traded forward Patrick Marleau to the Carolina Hurricanes on Saturday. That move cleared $6.25 million off the books for the Maple Leafs, according to Sportsnet's Chris Johnston.
Also, per TSN's Bob McKenzie, Toronto has an agreement on an extension in place for forward Kasperi Kapanen.