Diaz has not been involved for the Reds since the distressing events of Saturday in his native Colombia, with the wingers parents kidnapped.
His mother, Cilenis Marulanda, was swiftly rescued after roadblocks were set up around the town of Barrancas, but his father, Luis Manuel Diaz, is yet to be found.
On Tuesday, Marulanda led hundreds of locals marching the streets of the Diaz familys neighbourhood, demanding the release of Diaz Sr.
While police and military continue the search, an arrest has been made for one of the individuals believed to be involved in the kidnapping.
Colombian outlet Cambio reports that the bell ringer for the crime was detained at a residence in Barrancas in the early hours of Wednesday morning.
It is claimed that the suspect was the person who kept track of Luis Diazs parents, and who informed the kidnappers about the couples movements on Saturday.
The person detained is also believed to have alerted the kidnappers about the movements of the police and the army, but now he will be key to knowing the whereabouts of his accomplices and returning freedom [to Diaz Sr].
Cambio adds that Venezuelan authorities have informed their Colombian counterparts that the kidnappers did not cross the border into the country as feared.
Diaz has stayed on Merseyside following the events in his native country, with Liverpool providing staff to care for the player and his family in the UK.
According to the Mail, he has not travelled to Dean Court for Wednesdays clash with Bournemouth.
We spoke to Lucho, he wanted to go home, we sent people with him, have people there who take care [of him], Jurgen Klopp explained on Sunday.
There are parts of his family there as well, thats why they want to be together, thats absolutely understandable.
We got the news with the mum, which is fantastic, and since then nothing really. They all work on it, clearly.
Its quite some distance and we are obviously not the first people who get informed, but we try to get knowledge of everything as much as we can.
But we dont want to disturb in any way. We are not the important people there, we just want to support. Thats it.