KIERAN TIERNEY is on his way to Arsenal after they finally agreed a £25million deal with Celtic.

Media in the UK understand the 22-year-old is heading to The Emirates to discuss terms and have a medical ahead of tomorrow’s English transfer window shutting at 5pm.

The Gunners had been battling for the defender’s signature all summer.

But the Bhoys had turned down Arsenal’s £20m offer and were determined to get top dollar.

The Londoners finally upped their price and agreed a fee for the Scotland international.

He could now make his debut this weekend in the Premier League opener against Newcastle.

Celtic will also get a bumper sell-on clause with the astounding transfer package shattering the previous the Scottish record sale of nearly £20m for Moussa Dembele.

The Frenchman swapped the Hoops for Lyon a year ago.