Andre Villas-Boas slated for allowing stricken Spurs goalkeeper Hugo Lloris to play Andre Villas-Boas admitted that it was purely his decision to keep Hugo Lloris on the pitch after he was knocked out during the goalless draw at Everton. The Tottenham goalkeeper accidentally felt the full force of Romelu Lukaku's knee as the pair clashed when chasing a ball into the away box. Spurs' medical staff, along with captain Michael Dawson, urged Villas-Boas to take his man off. Both Lloris and Villas-Boas were advised that he should be substituted after being knocked out cold, but the manager insisted that his No 1 was capable of continuing - going against expert advice. Lloris had lay motionless for a number of seconds and Villas-Boas told Sky Sports: 'The medical department was giving me signs that the player couldn't carry on because he couldn't remember where he was. 'That is the situation right now. Hugo still doesn't remember the impact but he was quite focused and quite determined to continue. 'When you see this kind of assertiveness from the player it means that he is able to carry on. 'It was my call to delay the substitution, you have to make a decision in situations like this. 'From my knowledge of football he seemed OK to continue.' But Villas-Boas was accused of risking his goalkeeper's safety by overruling medical staff, who recommended that Lloris should be substituted. Leading football medic Mark Leather said: 'The guidelines are that players shouldn't be allowed to carry on and instead be monitored. It's a risk for managers to take medical decisions on that matter and the more serious the injury the bigger the risk. 'The consequences can be drastic, fatal even. You don't really know about internal bleeding for a period of time.' Villas-Boas countered: 'I made the call to keep him on the pitch because of the signs he was giving. 'When you see this kind of assertiveness from the player it means that he is able to carry on. He was determined to continue and looked concentrated, driven and focused enough for me not to make the call to replace him. The saves he made after the incident proved that right.' Lloris was knocked out in the 78th minute and after lengthy treatment appeared to be heading off, with Brad Friedel ready to replace him. Referee Kevin Friend also appeared to suggest a substitution would be the best thing to do. However, the France international began to struggle with members of the medical team guiding him to the touchline and indicated he was fit enough to stay on, leading to Villas-Boas giving the signal to let him have his way. 'Hugo still doesn't recall everything about the incident,' said Villas-Boas. 'The medical department were giving me signs that the player couldn't carry on because he couldn't remember where he was. 'It was a very difficult moment for us and I am happy he is well.' But Mark Leather, Bolton Wanderers' head of sport development and a former head physio at Liverpool, said the full effects of concussion often only come to light in the hours following an incident, and can prove extremely serious. He said 'I recall an incident in amateur football when a 16-year-old suffered a clash of heads and went home feeling unwell. 'Later he had a brain haemorrhage that resulted in a long stay in hospital. 'It seemed innocuous but there was a slow bleed in his brain and he had symptoms similar to a stroke. These kinds of occurrence are not common but equally not rare enough to be disregarded. 'Sometimes you get away with it. If you have an insistent player it is very difficult but I would do my damnedest to get them off and into dressing room to be assessed by a neuro specialist - you can't do that on the pitch.'