Steve McClaren has admitted that Aleksandar Mitrovic was "fortunate" to avoid a red card on his Newcastle United debut.
The Serbia international lunged in on Matt Targett soon after being introduced in the 75th minute against Southampton.
Referee Craig Pawson cautioned Mitrovic, while it was suggested by Maya Yoshida that the summer signing had also attempted to elbow him.
Speaking to Sky Sports News after the game, McClaren conceded: "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 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 joined Newcastle from Belgian side Anderlecht for a fee of around £13m in July.