After his exploits with Scotland at Euro 2020, Robertson was given an extended break as he enjoyed four weeks off – having clocked more minutes than any other Reds player last season.
Robertson is not set to be involved as Liverpool take on Mainz in their third friendly of pre-season on Friday, having undergone the lactate test under the Alps in the morning.
“In the off-season that’s the test you think about, and luckily it’s complete,” he told LFCTV after a series of running drills.
“Hopefully I’ll get a touch of the ball this afternoon and the hardest bit is over. It’s lovely to be back, I’ve missed you all!”
The 27-year-old – who marked four years as a Liverpool player this week – is likely to get his first taste of action when the Reds face Hertha Berlin in the final friendly of their Austrian training camp next Thursday.
So far, Klopp has called upon Kostas Tsimikas and Owen Beck as his left-back options, but Robertson will head into the new campaign as first choice again.
Liverpool have two further friendlies currently scheduled after the games against Mainz and Hertha Berlin, with Athletic Club (August 8) and Osasuna (August 9) the opposition at Anfield.
There is potential for the club to organise another friendly in the nine days between clashes with Hertha and Athletic Club, but no announcement has been made as of yet.