He'll just have to wait a little longer to make his debut.
Upon completing a reported €160-million transfer from Liverpool on Monday and signing a five-and-a-half-year contract with the Blaugrana, the Brazilian was ruled out for around three weeks with a pre-existing thigh problem.
But the news couldn't wipe the smile off his face. Once the Brazilian consummated his new contract, he presented himself alongside president Jose Maria Bartomeu and performed the customary kickieuppies as he greeted thousands of supporters at the Camp Nou.
Barcelona and Liverpool agreed to the megadeal on Saturday, with the former committed to paying a reported €120 million up front and a further €40 million in add-ons. Coutinho even covered a chunk of that amount to avoid any last-minute hitches, according to The Times' Paul Joyce.
Coutinho's buyout clause is also set at a whopping €400 million.
The 25-year-old long campaigned for this move to happen. Although his performances for Liverpool in the first half of the season showed no signs of distractions, manager Jurgen Klopp said Coutinho was "desperate" to join Barcelona. Neither Klopp nor Liverpool's owners were able to convince the Brazilian to stay.
He is now the second-most expensive footballer in the sport's history, behind only Paris Saint-Germain's Neymar. Kylian Mbappe will surpass Coutinho once PSG makes the on-loan teenager's €180-million transfer from Monaco permanent.
"I want to thank the president and everyone who has made it possible," he told reporters. "I am very happy, it's a dream come true, and I hope to be up to the job on the field."
He continued: "It's very emotional for me to wear the shirt of the most important club in the world. I am anxious to get going."
However, Coutinho won't have the opportunity to play for Barcelona in the Champions League knockout round because he is cup-tied. He already appeared in the tournament's group stage with Liverpool.
Coutinho missed Liverpool's first two matches of 2018 with the thigh injury. Some suspected he had exaggerated the issue to finally push through a deal that had been in the works since last summer. Back then, he complained of back pain right around the time Barcelona made its first bid.
The Independent reported in September that a scan revealed "nothing was wrong with him." Coutinho later represented Brazil in a World Cup qualifier, with the team's doctor noting that he was in "perfect condition" to play.
But Monday's medical at Barcelona's Ciutat Esportiva facility confirmed his current injury is, in fact, real.
Should he need the scheduled three weeks to recover, he would have a chance to make his Barcelona debut against Alaves at home on Jan. 28. He would also be in contention to face former side Espanyol on Feb. 4.
The midfielder has prior experience in La Liga, having played on loan at Espanyol during the 2011-12 season. That was long before he emerged as one of the world's best playmakers - a role in which he relished at Anfield.
Coutinho spent five years on Merseyside, registering 54 goals and 43 assists after arriving from Inter in 2013 for a measly €9.6 million.