By Adam Shergold for MailOnline
Published: 07:35 BST, 1 May 2019 | Updated: 07:38 BST, 1 May 2019
Arsene Wenger has expressed sympathy for Tottenham's medical team after defender Jan Vertonghen didn't immediately leave the field after suffering concussion during Tuesday night's Champions League semi-final.
The Tottenham defender went up for a header with team-mate Toby Alderweireld and Ajax goalkeeper Andre Onana midway through the first-half.
He was left lying prone on the ground in an awkward position, with blood pouring from a cut on his nose.
Ajax goalkeeper Andre Onana (right) took ball and all in an aerial collision with Tottenham defenders Jan Vertonghen (back) and Toby Alderweireld (left)
Vertonghen had to receive medical treatment after an ugly clash midway through the half
The impact of the incident was immediately clear as the swelling appeared on his face
Vertonghen received medical treatment first in the Ajax penalty area and then on the sidelines before changing his bloodied shirt and being allowed to continue.
But almost straight away, Vertonghen signalled to the Spurs bench that he needed to be replaced.
He appeared dizzy and even