Midfielder Nasri had hoped to sign for City by yesterday lunchtime after being promised a £180,000-a-week deal.
But Arsenal - also on the verge of losing skipper Cesc Fabregas - have blocked the move while they see if they can sort a swap with Tevez.
The Gunners will have to make a cash adjustment in City's favour for the Argie because the club's top scorer is valued at £50million.
The best Arsenal can get for Nasri is £25m as there is only one year remaining on the French star's contract - meaning he could walk for nothing next summer.
However, Arsenal are hoping to get the Tevez fee down by £10m.
And they believe they can come to an agreement over his wages which could be as much as £200,000 a week.
An Arsenal insider said: "Tevez would be just the signing to give everyone a lift.
"There is a lot of work to be done yet but if there is a will on all sides it can happen.
"Nasri wants to get to City, Tevez wants to get out and Wenger needs a new star to get everyone off his back.
"It seems like win-win all round."