So far Macken has suffered an injury-ravaged spell with the Blues, and when fit his progress has blocked by Robbie Fowler.
However, this season the City striker has been given his first run in the City line-up while Fowler has struggled for fitness, but he is yet to score in the league this term.
Keegan insists though, that as long as he keeps playing as he is, his starting role is not in danger.
"What Jon can do for us is get hold of the ball and give us a starting point," the City boss told the official website.
"He is not going to dribble past three or four players like Nicolas Anelka can but there are not many players who can do that. Jon is concentrating on what he is good at and by giving that to the team he is worth his place in the side and no one will quibble with his inclusion.
"The goals will come. He will score spectacular goals. I watched him do that a lot at Preston before I signed him.
"As long as he keeps doing a good job for the team and we keep getting results like we did against Chelsea on Saturday there is no pressure on him from me."
Keegan confirmed that, barring injury, Macken will start again at Newcastle on Sunday.
"Jon has done very well and was just about Man of the Match last week," he added.
"Robbie has to bide his time, but one thing is for sure - he is ready. And that is really important for us."