Liverpool will have 16 first-team players back at Melwood on Saturday, as Jurgen Klopp and his backroom staff oversee preparations for the 2019/20 campaign.
The Reds begin with a depleted squad due to summer internationals and, for some, ongoing tournaments, which rule out the majority of Klopp’s key men.
Joel Matip, Joe Gomez, James Milner, Alex Oxlade-Chamberlain and Adam Lallana are among the senior names involved, while last season’s loanees Nathaniel Clyne, Harry Wilson and Ryan Kent are included.
Arroyo is yet to receive a UK work permit, and therefore the 19-year-old has spent the last two seasons on loan with Real Mallorca and KAA Gent.
There is a noticeable lack of goalkeepers in the group, but Caoimhin Kelleher should back in time for the first friendly of the summer.
Liverpool begin their warmup at Tranmere Rovers on July 11, before a trip to Bradford City on July 14, ahead of the tour of the United States.
The likes of Jordan Henderson, Andy Robertson, Virgil van Dijk, Gini Wijnaldum and Naby Keita are expected back for that three-stop jaunt across the Atlantic, during which the Reds play Borussia Dortmund, Sevilla and Sporting CP.
Liverpool Squad Back for Pre-Season on Saturday