Kevin Keegan had no qualms about sending Joey Barton out for what proved to be an explosive final few minutes against Arsenal at Emirates Stadium - and insisted: 'He is going to have to play somewhere.'
Midfielder Barton was recently released early from jail following a conviction for assault and affray, and is set to face Football Association disciplinary chiefs next week after admitting a charge of violent conduct towards former team-mate Ousmane Dabo, with the possibility of a long suspension.
The former Manchester City man had not been expected to feature for the Magpies first team until after the outcome of the hearing, but was drafted into Keegan's squad following James Milner's departure for Aston Villa and a string of injuries.
Barton, who was introduced to jeers from the home support, weighed straight in with a hefty challenge on Samir Nasri.
The Arsenal winger then appeared to trip Barton off the ball, and was cautioned by referee Rob Styles, even though he did not see the incident himself.
It left Newcastle boss Keegan seething at the final whistle, when he confronted the Frenchman as they walked off the pitch.
The former England head coach, however, defended his tactics.
'You saw every player that I have got. That was it. That was why I decided to put Joey on the bench. It wasn't to do with anything other than that,' he said.
'Joey went on and, for five minutes, did well.'
Keegan maintained: 'He is going to have to play somewhere.
'As a manager, you look at the situation when you look around your bench.
'Habib Beye has had an Achilles problem and Jonas (Gutierrez) had run every blade of grass on the pitch. I'm scared of him pulling up like the left-back did.
'So I put Joey on because I looked at my bench and, to be honest with you, if you're doing your job properly he is the next player to put on as opposed to a 16 or 17-year-old kid.'
Keegan defended Barton's approach to his first competitive appearance for Newcastle since being released from jail.
He said: 'It was a good tackle. What you're probably saying is: 'Why did he come on and want to go into a tackle?' Because that's his game.
'That is what got Joey at Manchester City into the team and kept him in the team. That's what he does. He tackles.'
As for the hostile reception, Keegan accepted: 'Joey has got to get used to that and he's got to win through that.'
Despite the controversial end to yesterday's match, Keegan feels he can take some positives from yet another 3-0 defeat at Emirates Stadium, where Nicky Butt saw his header glance off the crossbar in the second half and Michael Owen had put the best chance of the first half wide.
He said: 'I am looking at the team and some of the new players I have got and I'm learning a little bit more about them.
'I think the two Argentinians (Jonas and Fabricio Coloccini) are going to be fantastic players for us - that's a positive - and young (Danny) Guthrie will get better and better.'
Keegan added: 'I know I have got some good men who care about the club around us.
'We need maybe two or three more. I think we have got a chance to take this club forward (if we get them). Not to where Arsenal are, because that is a big hop, but certainly to where the club should be with the support we get and the resources we have.'