The 27-year-old was announced as Bayern’s latest recruit on Monday – arriving on a season-long loan deal for an €8.5m loan fee, with Bayern covering the player’s wages.
And Grujic, who still plays for Liverpool, but who is on loan with Hertha Berlin, has no doubt that Coutinho will be a big hit in Germany.
“It is a big opportunity for the whole Bundesliga that we get the chance to see Coutinho,” he told Bild.
“He is a special player that is capable of crazy tricks and I enjoyed every minute of training with him at Liverpool.
“He will be the best footballer in Germany by far. Coutinho will be welcomed in Germany and hopefully he can show his talents here.”
Coutinho has scored 21 goals in 75 games in all competitions for Barcelona and produced 11 assists. He has won LaLiga twice and the Copa del Rey during his time with the Nou Camp outfit.
Bayern had announced on Friday evening that a deal “in principle” to sign Coutinho had been agreed, with their chief executive Karl-Heinz Rummenigge and sporting director Hasan Salihamidzic having been in Barcelona that week.
Rummenigge said on Monday: “We’ve been working on bringing in Philippe Coutinho for quite some time and we’re very happy that we’ve been able to complete this transfer.
“Our thanks go to FC Barcelona for agreeing to the transfer. With his creativity and outstanding skills, Philippe is a player who will immediately strengthen our attack.”
Salihamidzic said: “Philippe made it very clear to us during the negotiations in Barcelona that he absolutely wanted to move to FC Bayern.
“He’s a world-class player with great ability, who we can deploy in a number of positions in our forward line, so the FC Bayern squad has gained even more quality.
“Philippe Coutinho will help us achieve the ambitious targets we’ve set for this season.”