But the Scotland assistant insists the door is open for all strikers to work their way into the team.

Naismith was a surprise selection ahead of Griffiths and alongside Johnny Russell as Scotland opened their Nations League campaign against Israel.

But the 32-year-old Hearts player had a huge hand in the opener when his header went in off an Albanian defender before rounding off a 2-0 win by nodding home.

Leigh Griffiths was benched for the game against Albania and Steven Naismith could retain his starting slot against Israel. Picture: SNS Group

Manager Alex McLeish later admitted it would be hard to leave Naismith out in Haifa on October 11.

And, although he qualified his statement by saying it depends on form, Griffiths felt the statement had been a “kick in the teeth” to the other strikers in the squad.

However, the Celtic forward also vowed to work harder at his club to prove McLeish wrong and that was music to McFadden’s ears.

“It’s a great thing,” McFadden told Sky Sports News HQ. “You want competition. I want guys who are unhappy not to be playing, and that’s right.

McFadden: Wants players to be unhappy at not playing. Picture: SNS Group

“The manager’s comments were maybe taken a bit out of context. He didn’t mean Steven Naismith was going to be the number one striker and that was it, case closed.  “He meant that, from his performances, and the way he trained, that he was in pole position to hang on to the jersey.

“And quite rightly so, I would have given him the other goal as well and made it two goals.

“But we want Leigh Griffiths and guys like Oli McBurnie coming back in to be disappointed and take up the challenge, because there’s places there for everyone.  “We don’t have a settled squad. It was a fantastic start to the Nations League but we want the best players playing.

“And it is a challenge for Leigh Griffiths. He has a similar challenge at club level and he’ll have to fight the battle to get in the team both at Celtic and for Scotland. But that’s what we want.

“If he’s unhappy, great, if he comes with that attitude that he wants to show he should be in the team, even better.”

Naismith shows no signs of letting up though, netting his ninth goal of the season on Saturday against Motherwell as Hearts moved five points clear in the Ladbrokes Premiership.

“He’s sharp,” McFadden said. “Last season when he came into Hearts he looked as if he was lacking fitness and sharpness.

“Because he has had a couple of serious injuries, you were maybe thinking that was Naisy on the slide. But he’s had a fantastic pre-season.

“He had problems with his heel towards the end of last season and he seems to have sorted them out, he has a programme that he sticks to.

“He was breath of fresh air coming into the Scotland training, as was shown by his performances as well, and that’s why he was picked.”

Scotland coach '˜wants players like Leigh Griffiths to be unhappy at not playing'