Steve McClaren admitted new striker Aleksandar Mitrovic was lucky not to get sent off seconds into his Newcastle debut in their 2-2 draw against Southampton at St James' Park.
The Serbian made an instant impression upon replacing Papiss Cisse in the 75th minute, launching a scything challenge on Matt Targett which earned him a yellow card from referee Craig Pawson.
Mitrovic's actions drew criticism from Saints assistant Erwin Koeman - standing in for injured brother Ronald - who insisted: "I don't think he (Mitrovic) touched him, but if he did then Matthew was in hospital, I think."
And amid suggestions of a later elbow by Mitrovic on Maya Yoshida which went apparently unnoticed by Pawson, McClaren will be well aware of his need to curb his new striker's enthusiasm if he is to get the best from him this season.
McClaren, who claimed no knowledge of the second alleged incident, said of the first: "We were quite fortunate he did not get a red there and there would have been no complaints if he did.
"I don't know if he got that much contact but I'm just saying with the present rules of the game... I think in the olden days those kinds of challenges were 10-a-penny.
"That's what he (Mitrovic) is. He certainly doesn't hold back. He wanted to come on and impress. He's only a young lad and you can see how strong and direct he is. He is going to be a player."
Mitrovic's dramatic introduction certainly energised the home fans on a day in which it was another new signing, Gini Wijnaldum, who went the right way about stealing the show when he netted Newcastle's second in the 48th minute.
Wijnaldum, the pick of the home performers, finished off a fine cross from Gabriel Obertan just seconds after Yoshida had been denied a second for Southampton at the other end when his close-range strike was beaten out by Tim Krul.
Graziano Pelle had opened the scoring for Saints in the 24th minute before Papiss Cisse bundled an equaliser just before half-time. The visitors salvaged a point through substitute Shane Long in the 79th minute.
McClaren added: "I didn't quite know what to expect and I was absolutely delighted with what I saw - I thought for 75 minutes the team were excellent. We have learned so much and can we get better? Most definitely."
Erwin Koeman admitted his own satisfaction with a point after Thursday night's Europa League exertions were tempered by two golden opportunities spurned by striker Sadio Mane in injury time.
The acting boss said: "We had some big chances in the last 10 minutes but you have to score to win games so it is mixed feelings that we have.
"It is not a bad start but if you are professional and you get the chance to win you have to win. Ten minutes before the end I thought okay, we are happy with a point, but if you see the last 10 minutes then we have to be disappointed."