Coach Mike Babcock said the medical staff has a plan in place for Matthews and the are sticking to it.
It seems like Matthews is getting closer, but an exact return date is still unclear.
He is also tops on the Leafs with 12 power-play points.
Marleau also finished the game with a minus-1 rating and a giveaway in of ice time. He has 11 goals and 18 points in 33 games this season.
He got his seventh goal of the season to put Toronto up by a score of 4-1 after the first 20 minutes. The Leafs winger recorded all three of his points on the power play, which went 3-for-3 in the contest.
Matthews skated again in the morning, but he still needs to practice with the team before he can return.
The NHL confirmed the initial diagnosis after Lupul failed his team physical before training camp.
Toronto will place Lupul (.25 million) and Nathan Horton (.3 million) on LTIR once the season starts for some cap relief.
But Zetterberg was held to just three assists in seven games against the Lightning, who wrapped up the series with a 2-0 victory Wednesday at Amalie Arena.
It wasn't the only reason the Red Wings lost, but Zetterberg took much of the responsibility. We had a good chance but unfortunately we couldn't get it done," Zetterberg said. I couldn't really produce the way I wanted to this whole series. With the amount minutes I play I should be able to score more goals." Zetterberg averaged in ice time, third among the team's forwards behind Darren Helm () and Pavel Datsyuk ().