Messi has started the season in spectacular form, registering 12 goals and five assists in 11 appearances for Barcelona in all competitions to fire them to the top of La Liga and to the brink of qualification for the Champions League knockout stage.
"Right now, he's scoring goals, more goals than perhaps before".
"When I left Barcelona and went to Bayern Munich and Manchester City I never asked Messi to come here", said Guardiola ahead of City's game against Southampton on Sunday.
Barca might have had a sense of deja vu from their shock 2-1 defeat in Madrid by Leganes two months ago in which they also threw away the lead, and the Catalans adopted no-nonsense tactics to get back into the game, throwing defender Gerard Pique up front and playing frequent high balls into the box.
Luis Enrique is yet to pick him for Spain but it would be hard to justify ignoring the full-back again when the next squad is announced later this week.
"We've always said we can play against anyone, and that still holds true". "Under the new coach I'm not being picked but I'm working on it".
"It is a pleasure to see Messi play but I hope he can hold a little more on the bench", Zanetti said to Marca.
Rayo Vallecano fans were in good mood during the last seven minutes of the game thinking their team would record an emphatic win over Barcelona.
Upfront, Luis Suarez is another player who has stepped up in Messi's absence, and should be focal point of the Barcelona attack.
Their chances will be significantly boosted if Messi returns but the last fortnight will perhaps have given Barca greater belief too. They're now three points clear at the top of La Liga with 24 points from 11 games. If they must, they know they can function without him.