Goals from Kieran Morrison, Dominik Szoboszlai, Federico Chiesa and Lewis Koumas earned an impressive win for Iraola and his new side.
It was soured by Gomez’s injury, however, with the defender forced off after just eight minutes as the club’s crisis worsens.
Liverpool are now without captain Virgil van Dijk, who is on holiday following the World Cup, and Giovanni Leoni, who are is yet to return from long-term injury.
New signing Jeremy Jacquet was left out as a precautionary measure, but he too has only just come back from a shoulder issue.
Speaking to LFCTV after the game, Iraola spoke about Gomez’s injury, saying: "Probably the worst news has been straight away 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 has also confirmed that Liverpool fans should see Jacquet sooner rather than later.
"With Jeremy we decided to take it easy with him, he's had a lot of months without playing, he's been training very well, but we're going to take it easy with him,” he added.
“He will play probably in the last game of this U.S. tour, he will have time to have minutes, but we were kind of happy, but we've lost one now."