The centre-forward is one of a number of Millers players out of contract at the end of the season, although in many cases - including Smith’s - they have the option of extending their deals for another 12 months.
And Smith could be in demand. The interest Warne feared in the last two windows was not forthcoming but with the pain of behind-closed-doors football further in the background, Smith’s contract situation and 24 goals so far this season, this summer could be different.
If it is, Rotherham might have to change too, not that Warne is resigned to having to replace his talisman.
“It will be incredibly difficult, as it was when Crooksy (Matt Crooks) left, when Will Vaulks left, when Semi (Ajayi) left and it might be that we sign a different type of player, play a different type of way to accommodate the fact we haven’t got an archetypal No 9,” he argued. “They are a dying breed.
“There aren’t many teams that play with an out-and-out nine.”
Smith, who joined Rotherham from Bury in 2018 and is settled in South Yorkshire, has 18 goals in this season's League One, a total bettered by only five players.
But the hope for Rotherham is that Smith and others in the same boat will be persuaded to stay if the Millers can close out promotion to the Championship. They are top of the table and still will be next week because although Saturday's game has been postponed because of international call-ups, so has Wigan Athletic's.
More importantly, the gap to the play-off places is four points with Rotherham and the teams in those positions all having seven matches to play.
"If we go up, will it be easier to get Smudge to sign? Yeah, it would be," said Warne. "But easy enough? I don't know. That's the truth.
"Me and him are pretty close I like to think, we've had many conversations, we're both honest, but there'll be a conversation to have with him when we know where we are. It will make it easier because the finances in the Championship for us are more competitive than in League One. However, if another club wishes to come and spend the cash it's going to be difficult.
"But it doesn't mean we can't try and be creative and try and keep him.
"If his time is up and he does leave in the summer he goes with everyone's fondest thoughts and thanks. He's been brilliant for us.
"I hope that isn't the case but we'll wait to see."