Mark Hughes's future at Manchester City has entered a critical period as he battles to convince the club's owners over the next few weeks that he remains the manager to realise their long-term vision.

The City manager is again under scrutiny following Wednesday night's meagre offering at Tottenham Hotspur, where a 3-0 defeat to fellow Champions League hopefuls left the club languishing eighth in the Premier League. This comes amid reports that the former Chelsea manager Guus Hiddink has been approached by City's chief executive, Garry Cook, about taking over in the summer.

Hiddink's agent, Cees van Nieuwen-huizen, told the Daily Telegraph: "He [Cook] asked me if it would be worthwhile having a meeting to discuss the future and what might happen next summer. But I told him Guus was contracted to Russia."

City have now won one, lost one and drawn eight of their last 10 league matches and despite receiving unequivocal support from the chairman, Khaldoon al-Mubarak, and the club hierarchy in the past, Hughes is under renewed pressure to oversee an upturn before the January transfer window.

City face Sunderland, Stoke City and Wolverhampton in their final league fixtures of 2009, a trip to Middlesbrough in the FA Cup third round on 2 January and then the Carling Cup semi-final with Manchester United. The prospect of guiding the club to its first major final since 1981 can be presented as evidence of tangible progress by Hughes, who appeared to have revived City's season only a fortnight ago with victories over Arsenal in the Carling Cup and Chelsea in the Premier League.

City's owners, however, have higher ambitions for the season following an outlay of £118m on new players last summer – notably a sustained challenge for Champions League qualification – despite their acknowledgment that there will be inevitable dips in the rebuilding process.

Hughes confirmed following the defeat at White Hart Lane that he intends to return to the transfer market in January and the next few games are seen as key to retaining the confidence – and financial support – of his employers in Abu Dhabi.

The performance against Spurs represented a severe setback to those aims, while Gareth Barry's admission last night that the players were "at each other's throats" in the dressing room afterwards would not have gone down well either. "There is a minimum requirement in terms of work-rate and effort and we didn't have a platform to be able to get into people's faces and close people down," the City manager conceded. "We don't profess to be the finished article and that was shown. We have a big game at the weekend and it is important we get back on track."

The former Wales and Blackburn Rovers manager has overhauled City's football operation since Sheikh Mansour bought the club in 2008 and there is reluctance among the owners to start anew. Equally, they also want evidence that City can compete in one of the most open Premier League seasons for several years.

Hughes's task has not been helped by untimely injuries to defenders, the latest being the knee problem that has sidelined Joleon Lescott for between six and eight weeks. The England international underwent surgery in London on Wednesday to remove a piece of bone that came loose when he hyper-extended his knee during the 3-3 draw at Bolton Wanderers last Saturday. Lescott joins Wayne Bridge in the treatment room, with the left-back also out for six weeks with a knee problem, and with Kolo Touré bound for the Africa Cup of Nations next month the City manager hopes to reinvest in January.

"We will see what's out there," said Hughes, who also has Nigel de Jong suspended for the match with Sunderland tomorrow. West Ham United's Matthew Upson and Neven Subotic of Borussia Dortmund are among the possible candidates for a new City central defender.

The Eastlands club have a game in hand on the four teams immediately above them in the Premier League and Barry, Hughes's first expensive recruit for this season, admitted there is plenty of scope for improvement on the side's showing at White Hart Lane. "We are very disappointed and we are really hurting in the changing room and the lads were really at each other's throats," he said.