Arsenal and Chelsea have joined the queue of clubs keeping a check on Nigerian prospect Henry Onyekuru. The 19-year-old winger plays for Eupen in Belgium and was a target for Celtic in January who had a bid of £1million rejected. Onyekuru went AWOL for several days in the hope of pushing through a transfer to Glasgow but has since returned to action and has been given assurances he can leave in the summer. The Belgians though are looking for £6million with the fee key to Onyekuru being able to gain a work permit in the United Kingdom. Onyekuru has scored 12 goals in 26 games this season, including the winner against Gent earlier this month, when he impressed several watching scouts. Sevilla, Borussia Dortmund, Monchengladbach and Lille have also sent staff to check on his progress in recent weeks.