Second-half goals from Dominik Szoboszlai, Federico Chiesa and Lewis Koumas saw the Reds ease to victory at Geodis Park with Joe Gomez's latest injury setback the only concern.
Gomez was given the captain's armband by Iraola, but he was forced off after just 10 minutes due to a muscle issue, after immediately signalling to the bench over the problem.
Ifeanyi Ndukwe replaced Gomez, to line up in central defence alongside fellow 18-year-old Mor Talla N'diaye - as Iraola admitted his concern a full-time.
"Probably the worst news has been straight away with the injury of Joe. We were happy because we were going through training without losing any players and unluckily for us we've lost Joe straight away."
Iraola did not offer any detail on the injury or Gomez's expected return at this stage and N'diaye and Ndukwe could start against Wrexham on July 29.
Club captain Virgil van Dijk is still away on his summer break with Giovanni Leoni still working on his ACL recovery and new signing Jeremy Jacquet not match fit.