Left-sided Touba was born in France, but cut his teeth in Belgium, coming through the Club Brugge youth set-up and then switching to the Netherlands with Waalwijk in 2020.
He has established himself at the Dutch side and his performances brought a breakthrough to the Algeria team on the international stage.
Touba is wanted this summer and, according to French outlet Foot Mercato, Celtic and Olympaicos both want to sign him.
The 24-year-old made 28 appearances in the Eredivisie in the recently concluded campaign, being booked seven times as Waalwijk recorded a finish of tenth.
Touba is entering the final year of his contract at the Dutch club and may be attracted by the idea of a move away to further his career.
Both Celtic and Olympiacos are able to offer the Algerian the chance of Champions League football next term.
Touba has now been capped five times by Algeria, with his latest coming on Sunday against Iran.
