Liverpool have been one of the form teams across Europe's top five leagues this season. After seven games, the Reds are the only unbeaten team in the Premier League. They have also fared well in the Champions League, beating AC Milan 3-2 at home and winning 5-1 at Porto.Jurgen Klopp's men have benefitted from the prolific exploits of Mohamed Salah and Sadio Mane up front. At the other end of the field, Virgil van Dijk's return has reinvigorated a beleaguered backline that struggled to keep out opposing teams last season. Considering their start to the season, Liverpool could make a deep run in the Champions League and even win their second Premier League title in three years.On that note, here's a look at the five most valuable Liverpool players at the moment:Note: All player valuations and stats are as per Transfermarkt unless mentioned otherwise.#5 Alisson - €60 millionAlisson has had a good start to his campaignAlisson is widely regarded as one of the best goalkeepers in the game at the moment.The Brazil international has played a crucial role in Liverpool winning the Champions League and Premier League in successive seasons. He has kept an impressive 63 clean sheets in 139 games across competitions for the Reds, with four of them coming this season.Last season, Alisson became the first goalkeeper in Liverpool history to score a competitive goal when he headed a 95th-minute winner against West Bromwich Albion.Premier League@premierleagueAlisson is the first goalkeeper ever to score for Liverpool#WBALIV11:02 AM · May 16, 2021371194933Alisson is the first goalkeeper ever to score for Liverpool#WBALIV https://t.co/wBOaTm2IqbThe 29-year-old is an integral player in Jurgen Klopp's team, a quintessential ball-playing keeper who helps build attacks from the back and is reliable with his glovework.#4 Andy Robertson - €65 millionAndy Robertson is an important player for LiverpoolAndy Robertson is a key cog in Jurgen Klopp's system. Together with Trent Alexander-Arnold (more on him later), the Scot forms one of the most devastating full-back partnerships in the game's history.Since arriving at Liverpool more than four years ago, Robertson has scored just five times in nearly 200 games across all competitions. However, he has racked up an impressive tally of 38 assists, including 12 in Liverpool's triumphant 2019-20 Premier League campaign. Andy Robertson@andrewrobertso5Scoring is the new assist 👀 #YNWA11:50 AM · Nov 2, 2019814967509Scoring is the new assist 👀 #YNWA https://t.co/6EQf6LTC5yRobertson has provided only one assist in seven games across all competitions this season. However, he is expected to play a key role as Liverpool look to compete on multiple fronts.