Miguel Herrera has decided to leave Javier Hernandez out of his Mexico squad so that he can sort out his future.
Sky Sports understands that Dinamo Zagreb striker Duje Cop is attracting interest from clubs across Europe.
Riga has taken control of a side that currently has just six senior players on its books.
Additions are imperative in the summer transfer window, and plenty of them.
Riga insists there is cause for alarm, though, and has vowed to take his time as he searches for the necessary fresh faces.
He told the Gazette: “Recruitment is a process we won’t be rushing.
“We want to do things properly and step-by-step to make sure we don’t make mistakes.
“I know we have a shortage of players. We can’t play with a squad of six, but we have a strategy.
“We’ll be working straight away to address this.”
Riga is also in the process of piecing together a backroom team, with Blackpool having spent a large chunk of the 2013/14 campaign working under the tutelage of caretaker boss Barry Ferguson.
He added: “I have ideas about my backroom staff and will have those discussions.
“It’s important I have a good team.”