The Colombia international joined the club from Porto for a transfer fee of £42.30 million back in January.
Diaz performed well during his first six months at the club. The 25-year-old scored six goals and registered five assists in 26 appearances for Liverpool's first-team.
With that being the case, Merson believes opposition teams will be looking to nullify Diaz this season.
"Unlike last season, (he) is on the radar this time around. When he first joined, team talks from opposition managers wouldn’t have really been about him," he told the Liverpool Echo, as quoted by Anfield Watch's Twitter account.
"But now he’s quickly made the left wing his own and will find it harder to make an impact this season. He’s been a fantastic addition for Liverpool and should continue from where he left off last season.”
With the signing of Carvalho and the brilliance of Firmino, could we see Jurgen Klopp deploy a formation change this season?
Playing 4-2-3-1 with one of these ballers in the middle could be magical 😍 pic.twitter.com/FDmcwGYreq
Anfield Watch Verdict
We can see where Merson is coming from. However, Diaz is strong enough to deal with extra attention.
The exciting thing about the winger is that he is only 25 years of age. Diaz is entering the prime years of his career.
The Colombia international is also completing a full pre-season under Jurgen Klopp, which is something he has never done before.
Therefore, we are confident that Diaz will overcome any challenges thrown at him this season.
All we will say is that the Anfield faithful should be excited about what could happen next season with the aforementioned players representing the club.