Carlos Tevez insists he must up his game for Manchester United this season or face losing his international place to Argentina's golden youngsters.The striker was on top form last night despite the Red Devils' 2-1 defeat to Zenit St Petersburg in the UEFA Super Cup, and admits he has been spurred by his country's retention of their Olympic title in Beijing. It was the 24-year-old who led Argentina's successful campaign in Athens in 2004 but he insists the emergence of a new generation of stars has given him renewed motivation to prove his worth - and that can only be good news for United. 'It will benefit me and Manchester United because I treasure playing for my country,' Tevez told The Sun. 'And I know from what I've seen in the Olympics that if any of us in the national team rest on our laurels, then these brilliant youngsters will have our places. 'It's an incentive to work harder and win things all the time. 'I know how strongly the youngsters will be pushing us - given that the same happened when I won the gold medal in Athens.'