Roberto Mancini is facing an uphill battle to convince City’s board to bring Samuel Eto’o to the Etihad Stadium in a straight swap for Carlos Tevez.

Argentinian striker Tevez, 27, was set to return to Carrington today – but has now been given extra time off and will be back on Monday following his post-Copa America break.

Blues officials value Tevez at £50million, and believe that he is worth significantly more than Inter Milan striker Eto’o, who turned 30 in March.

It is understood that the City board are extremely reluctant to consider a swap deal, particularly one that would see them receive a striker with a limited sell-on value.

The club hierarchy have also privately indicated their unhappiness at the prospect of doing business with Eto’o, who showed little enthusiasm when he was offered a move to Manchester in 2009.

Eto’o, then with Barcelona, exasperated Blues officials by dawdling over a contract offer worth a reputed £180,000-a-week after tax.

City got so sick of waiting for a response that chief executive Garry Cook made a public statement declaring that the club were pulling out of the deal.

Since then, Eto’o has declared an interest in moving to the Premier League – for what would be a final bumper contract before retirement – with Mancini interested in  a deal.

Inter, for their part, are keen to sign Tevez, who declared last month that he wanted to leave City. However, the Blues have yet to receive a bid, and see no urgency to sell if they do not receive an offer matching their valuation.

Mancini has not always seen eye-to-eye with City’s board on transfer policy, stating at the start of the summer that he wanted more control, and it is understood that this has led to tension behind the scenes.

But the club hierarchy have endeavoured to make it clear to him that they have to be more careful with their spending in order to ensure they fit in with UEFA’s pending financial fair play rules.

The rules, which will govern clubs playing in UEFA competitions, will allow clubs to lose a maximum of £38.5million over the next two seasons.

Clubs who miss that target, though, will escape sanctions – such as a European ban – if they can show both a downward trend when it comes to losses and that their overspending has been caused by commitments on wages and transfer fees made before June last year.

Those caveats do give a degree of leeway to City, who lost £121m in the 12 months up to May 31 last year – but still mean that it would be unwise to repeat the spending sprees of recent summers.

Meanwhile, new signing Sergio Aguero – who was not expected to make the starting line-up for Sunday’s Community Shield clash with neighbours United – was forced to miss an open training session at the Etihad Stadium yesterday due to a stomach bug.