The 29-year-old has already hit seven goals in his first 10 League One outings this term, and was on target twice as the Millers beat AFC Wimbledon on Tuesday evening.
Despite his heroics in front of goal, however, United manager Paul Warne suggested that the forward still has more to offer.
And speaking on last night’s edition of EFL on Quest, Murray backed the striker to continue his impressive streak of form.
He said: “They’re putting a really good run of results together.
"Warney was saying he wanted more out of Michael Smith – we’re going to start his fan club then, because he’s got seven from eight.
“Fair enough, he sees him every day and he says he can be even better. Well, that’s scary!”
Pundit Jobi McAnuff agreed, adding: “Exactly, especially when he’s started the season as he has this year.
"I think from his point of view, he hasn’t actually hit double figures in League One yet, so that’s a real good target for him, and he’s certainly made a good start to it.”
Murray added: “He’s going to smash that this season.
"It’s going to be a very good season for him.”
Warne has previously suggested that Smith was an “irreplaceable” part of his plans at the New York Stadium.
Speaking towards the end of the summer transfer window, he said: “If you ask me what Smudge is worth to me, I'd say £10 million. He's irreplaceable for me as a manager.
"A striker who wins heads, hold up the ball, scores goals and work hard is a good asset for any club."