The club has already paid Osasuna €40m for Spain international Victor Munoz, while centre-back Jeremy Jacquet, signed from Stade Rennes back in January, has now linked up with the squad after finally arriving in the summer.
Speaking to ESPN, Iraola was candid about the scale of the work still to come.
"Obviously we've signed two players already but we need more players, we know this," he said. "The club is working on this.
"Me as a coach, selfishly I want the players here from day one ready to train for preseason but understand football doesn't work like this. I know the club is working hard for those signings and I'm trying to help also."
According to The Athletic, Liverpool have narrowed their search for further attacking reinforcement to a shortlist of four names.
Bradley Barcola, 23, remains admired by the club, with his situation at Paris Saint-Germain continuing to be monitored closely. Also under consideration are Brighton's Yankuba Minteh, 21, Said El Mala, 19, of Cologne, and Lille's Matias Fernandez-Pardo, 21, with all three understood to be genuine targets rather than speculative names.
Beyond the winger position, Liverpool are also looking to strengthen their midfield, even as uncertainty hangs over the futures of several existing squad members. Curtis Jones, Federico Chiesa and Harvey Elliott are among those whose long-term places at the club remain unclear heading into the new season, giving Iraola a squad in a genuine state of transition as he begins his first full campaign in charge on Merseyside.
Munoz's arrival gives Iraola a versatile attacking option who can operate across the front line, though his signing alone was never going to be viewed as sufficient given the size of the void left by Salah's departure.
With four credible targets already identified according to The Athletic's reporting, the coming weeks look set to be pivotal in determining how completely Liverpool can address their attacking options before the transfer window closes and the new Premier League season gets under way.