Barcelona have stepped up their attempts to bring Coutinho to the Nou Camp and have already had a £72million bid rejected by Liverpool.
Jurgen Klopp has repeatedly insisted the Brazil international is not for sale at any price.
Coutinho seemingly put any rumours of him leaving in the near future back in January when he signed a new long-term contract with no release clause.
At the time of signing his contract, Coutinho said he plans to stay for a few more years.
But Carragher believes the 25-year-old will find it hard to turn down a move to Barcelona should they make a big-money offer next summer.
"Hopefully we can get 12 more months out of him," Carragher told 5times.co.uk.
"When he signed his five-year deal, I didn't think that he would see it out.
"There is no doubt that at one stage in his career Philippe will want to play for one of the Spanish giants as many of the South American players do.
"Barcelona and Real Madrid are seen as the two biggest teams in world football who always have the best players.
"I think that Liverpool fans should really enjoy him over the next 12 months as if a big money offer does come in at the end of next season and if the player wants to play for Barcelona then there is not really much Liverpool can do.
"Like I said, let’s just hope we see him in a Liverpool shirt next season, which I think we will, and then let’s see where things go from there.”
