Liverpool's problems at the back restricted their progress until Virgil van Dijk arrived at Anfield in January and completely transformed the defensive unit. 

Indeed, Jurgen Klopp's attacking brand of football has made Liverpool an exciting side to watch since he took charge in 2015, but he has struggled to strike a balance between forward-thinking optimism and defensive solidity throughout his time at the helm.

But after various players failed to establish a strong connection in central defence, Virgil van Dijk walked into the club and changed everything.

His natural leadership qualities and exceptional defensive attributes have installed the elusive solidity into Liverpool's defence, making them strong contenders to lift the Premier League title in the process.

Van Dijk is just one of a multitude of players who have swapped Southampton for Liverpool, but it was Scottish giants Celtic who provided him with the platform from which to build his career.

The Hoops signed Van Dijk from FC Gronigen for a fee of £2.7 million in 2013, and in the space of just two seasons he established himself as a firm fan-favourite whilst attracting interest from south of the border.

Van Dijk immediately established himself as a mainstay at the heart of defence by making 35 starts in the SPFL on his debut season for the Hoops, scoring 5 goals in the process.

Although his formidable defensive presence was the most prominent aspect of Van Dijk's impact, his goal-scoring prowess proved to be a valuable weapon for Celtic.

He carried his impressive record in-front of goal into his second season for the club by notching 10 times in all-competitions, taking his tally to 15 for the club before Southampton forked out £13 million to bring him to the Premier League on September 1st 2015.

That Southampton - a mid table Premier League side - managed to sign Van Dijk ahead of their domestic rivals suggests that the top clubs were unwilling to fork out for a player who was unproven outside of Scotland, and Liverpool paid the ultimate price for failing to recognise his talent early on.

Whilst Celtic pocketed a shrewd £10.4 million in profit from Van Dijk's sale, Southampton went on to earn a whopping £62 million.

Celtic's decision to sell Van Dijk put the Netherlands international in a position to justify his beaming reputation to some of Europe's biggest clubs, and it's fair to say it was the transfer which paved the way for Liverpool to find the ideal solution to their defensive woes.

Liverpool fans - thoughts? Let us know below!