Jurgen Klopp says Liverpool got lucky with Andy Robertson despite the full-back being ruled out of the start of the season with an ankle injury.Robertson revealed on Monday evening that he will miss the start of Liverpool s Premier League campaign due to ligament damage. The left-back limped out of the Reds 1-1 friendly draw against Athletic Bilbao on Sunday and was pictured wearing a protective boot on his right foot.The injury initially appeared to be serious, with Klopp saying on Sunday that it was a pretty painful blow for Robertson.But the managers update following Liverpools 3-1 win over Osasuna in their final pre-season match on Monday will offer some reassurance to fans.Robertson limped out of Sunday's match against Athletic Bilbao (Andrew Powell/Liverpool FC via Getty Images)I think we got lucky with that, it could have been much worse, Klopp told LFCTV.The footage didnt look too well, got lucky but it wont be too long. Before or after the international break, I dont know. Not too long.Obviously, [its] really good to have Kostas [Tsimikas] back, and Owen [Beck] which is nice as well.Klopps prognosis means Robertson could be due back fairly soon, given the first international break in the Premier League season runs from August 30 to September 8.That is just a fortnight after Liverpools campaign opener at Norwich on Saturday and is for World Cup qualifiers, with England playing Hungary, Andorra and Poland. How big of a miss will Andy Robertson be for Liverpool? Have your say in the comments section below. Robertson started all 38 of Liverpools Premier League games last season, contributing one goal and seven assists, but will now miss the start of the 2021/22 season."Thanks to everyone for the kind messages and support, he wrote on social media.Scan suggests nothing too major but theres some ligament damage which will need to mend."I will be grafting every day so I can help the team again sooner rather than later. Good luck to the boys playing tonight #YNWA."While Robertsons injury is undoubtedly a huge blow to Liverpool, supporters will take heart from Tsimikas pre-season performances.The Greek international was signed from Olympiacos last summer for £11.75million to provide back up to Robertson, but endured a nightmare first season due to injury.Having made just seven appearances in all competitions, Tsimikas now looks set to play a much more important role in the upcoming campaign.He looked impressive against Osasuna, putting in a brilliant first-time cross for Roberto Firminos first goal while also taking set pieces. "I always give my best to be close to the team, Tsimikas told the club website following Liverpools 1-0 friendly win over Bologna last week. And whenever my coach gives me the opportunity to play, Im always ready for that. Any opportunity, Im ready." Get your hands on your club's special edition 2021/22 annual. Find out more here.