The club’s penultimate preseason match was dampened when Robertson, 27, appeared to sustain a serious ankle injury before half-time which saw him replaced.
The match was played in front of Anfield at 75% capacity — the biggest crowd at the ground since the start of the coronavirus pandemic.
Kickoff was delayed by 30 minutes after thousands of supporters queued outside to enter the stadium.
There was good news for Liverpool as Virgil van Dijk started the game and received a standing ovation when he was substituted after 71 minutes.
Jurgen Klopp’s side take on Osasuna in their final preseason match before they begin their Premier League campaign away at Norwich City on Aug. 14. Athletic face a trip to Elche on Aug. 16 for their first league match.