Celtic have agreed a £3.4million deal with PSV Eindhoven for midfielder Joel van den Berg. [Sky Sports]

The Netherlands Under-19 international is expected to travel to the UK on Monday, where he will undergo a medical and complete the remaining paperwork before joining Martin O’Neill’s squad.

It is a deal that has moved quickly, and comes with Celtic now firmly into the business end of the summer window.

Van den Berg is believed to be the man Celtic have settled on following Arne Engels’ £22m move to West Ham earlier this month. Engels’ departure brought a significant fee into the club, but it also left O’Neill short of another midfield option at a time when the squad was already in need of strengthening.

The £3.4m move for van den Berg should begin to address that.

There will naturally be plenty of interest in a teenager arriving from PSV for that sort of money, particularly when he is being brought in after such a big-money departure. Celtic, though, clearly see something worth investing in.

And they cannot afford to hang about.

The Scottish transfer window closes at 5pm on Thursday, September 3, meaning Celtic have only a few days left to get the rest of their business done.

There is a little quirk to this deadline week as well. Clubs in England have to stop buying at 11pm on Tuesday, leaving Scottish sides with another two days to operate.

That could become useful.

Players who have been waiting on moves in the Premier League or Championship could suddenly find their options narrowing once Tuesday night passes, while English clubs may also be more willing to sanction departures once their own incoming business is finished.

Celtic still have areas of the squad that need attention, so nobody at Parkhead should be shutting the laptop once van den Berg is through the door.

But getting another midfielder in was important, particularly after losing Engels, and this one now looks close.

Van den Berg is due in the UK on Monday. Assuming there are no problems with his medical or the final paperwork, Celtic should have their latest summer signing wrapped up with time still left to do more before Thursday’s 5pm deadline.