The 4-1 victory was overshadowed slightly by Gerrard's apparent forearm to the back of Brown's neck in the second half, after which the Liverpool captain was immediately substituted by Benitez.
"I don't think so," said the Spaniard when asked if he was worried about retrospective action against his captain.
"I haven't seen it but I was asking and I think it was nothing."
Benitez also played down the immediate substitution of Gerrard, adding: "We were thinking of changing Torres, Glen Johnson and Gerrard and we did it."
Only a week ago Gerrard found himself in a similar situation for an alleged v-sign made at referee Andre Marriner in the defeat at Wigan.
That went no further as the official said he had seen the incident at the time and decided it did not warrant any action.
On Monday night, referee Stuart Attwell was very close to the incident but took no action but it remains to be seen whether he will be asked to look at it again by the Football Association.
Portsmouth manager Avram Grant said he also did not see the incident but felt Attwell should have spotted it.
"I didn't see it. I will speak with Michael Brown and then I will tell you," he said.
"They told me the referee was four metres away from this so I think the referee needs to see from four metres what I didn't from 40 metres," he said.
"Personally I like Steven Gerrard. I think he is a good player and a fair player."