Barcelona are strongly pursuing the Brazilian playmaker and Gerrard acknowledges it would be a risk to keep Coutinho against his will.
"It is very very difficult, especially for the owners of Liverpool football club who are going to be under big, big pressure from our supporters at Liverpool to keep hold of Coutinho," Gerrard told BT Sport.
When asked if it's worth keeping a disgruntled player anyway, Gerrard replied: "Yes and no.
"You'd like to think that Philippe's professional enough, once the transfer window's out the way, to pick himself up and be professional enough to get on with it.
"But at the same time, you do run a risk of keeping a very unhappy player because he might (not) play at the levels you'd expect from him."