The Daily Telegraph says Liverpool's resolve over Coutinho's future has strengthened after Barcelona's kit manufacturers Nike advertised the club's shirts with the Brazilian playmaker's name on the back, suggesting that a transfer was close to completion.
Coutinho, 25, was the subject of three transfer bids from Barcelona during the last summer transfer window – the biggest of which amounted to £115m ($155m) – but Liverpool remained adamant that he would not be sold for any price.
The Brazil international ended up filing a transfer request in an attempt to force through a move, but Liverpool manager Jurgen Klopp and owner Fenway Sports Group refused to alter their stance.
He reportedly still has his heart set on a move to the Catalan capital, although Nike's marketing blunder is bound to create fresh friction in negotiations between Liverpool and Barcelona.
The advertisement, which was displayed briefly on Nike's online store over the weekend, read, "Philippe Coutinho is ready to light up Camp Nou. Get your 2017/8 FC Barcelona kit with the Magician's name on it. Act fast – free personalisation only available until January 6."
Coutinho, who is also endorsed by Nike, was left out of the Reds squad for the 2-1 win over Burnley at Turf Moor on New Year's Day due to a thigh injury.
Last month, the Brazilian said that his future at Anfield remained uncertain.
"I am at Liverpool and I always do my best when I have the opportunity to play, respecting the jersey and the supporters," Coutinho was quoted as saying by The Sun.
"I do not know how the future is going to be. What will happen in January, we will know it in January. I don't know if there will be an offer.
"Last summer, there was a job offer in the same way that happens with any employee and I was interested in it. Since I stayed I have played with will and desire."
Coutinho signed a new five-year contract at Liverpool worth around £150,000 per week last January, making him the highest-paid player at the club.
He has made 20 appearances in all competitions for the Reds this season, scoring 12 goals.