Coutinho made the move to the Allainz Arena for a season-long loan to the Bundesliga champions, with Bayern reportedly holding a potential purchase option.
The Brazilian is looking to put a difficult 2018-19 campaign behind him and has earned rave reviews from his new head coach, Niko Kovac, and others since his arrival.
He made his debut for Bayern off the bench in a 3-0 win over Schalke this weekend, and the former Real Madrid midfielder Mascarell believes Coutinho will make the Bavarians’ attack even more potent this season.
“It's great news that Coutinho plays in the Bundesliga,” Mascarell told Goal and Spox. “He was certainly the player that Bayern needed – one who provides danger between the lines with his power of shooting and combination.
“He will definitely harmonize perfectly with Thiago and Robert Lewandowski.”
Bayern coach Kovac heads into his second year with the Bundesliga giants, having won a domestic double in his debut season.
Despite his success, which saw him equal or surprass the work of his predecessors in recent years, stumbles at points during the campaign as well as elimination in the Champions League saw him come in for criticism.
But Mascarell, who played for Kovac at Eintracht Frankfurt and won the DFB-Pokal over Bayern Munich in 2018 alongside him, believes the coach has been underserving of such harsh critiques.
“Niko has not only made me a better footballer, but has also developed me as a human being,” Mascarell said. “I do not understand those who question him and his footballing expertise.
“It has been seen with us that he pursues a clear game philosophy, can play many tactical systems and cope with his players.
“He is the type of coach who criticizes you if you have not given everything. Then it's time to roll up your sleeves and do it fast.
“Niko can get very loud in the dressing room, but he's also very fair and praises you when you've done your job.”