Coutinho's future has been thrown into doubt in recent days, with reports in Spain suggesting that Barca officials have travelled to England in order to push through a €100m (£89.45m, $116.5m) deal for the Brazil international, who has been identified as a potential replacement for Neymar.
Coutinho, 25, signed a long-term deal with Liverpool earlier this year but Barcelona will be flush with cash if his compatriot joins Paris Saint-Germain in a deal that could be worth almost £200m.
Neymar himself has expressed his desire to see Coutinho arrive in Catalonia in recent months, but Nicol thinks Liverpool will hold firm over their coveted attacker "regardless" of the astronomical offers they may receive due to the adverse effect it would have on the supporters and the squad.
"I absolutely do, 100 per cent [think Coutinho will remain at Liverpool] ," Nicol told ESPN. "He is arguably Liverpool's most influential player, certainly was for the last couple of seasons. To let him go would be a huge blow not only to the fans but the rest of the team. I don't think Liverpool would do that regardless of the offer, and I hope I'm right.
"I think [Jurgen] Klopp has got himself a base, he's got himself into the top four. Now it's about kicking on, and you can't do that if you let your best and most influential players go. It just can't happen for me."
Barcelona's interest in Coutinho was made public long before PSG's pursuit of Neymar. The view from some quarters was that the former Inter Milan wonderkid would succeed the iconic but fading Andres Iniesta in a central midfield, but Nicol is adamant Coutinho is best suited to playing out wide and believes he would not receive much in the way of game-time if Neymar remained at Barcelona.
"The fact that Neymar may leave Barcelona would mean Barcelona would be alerted to the fact that Coutinho is someone who could replace him," Nicol added. "Why would Coutinho go if he's not going to play? His best position is in a front three. There is no question Coutinho must play as part of a front three, if you put him further back, you lose something."