The Chinese super league side Tianjin Quanjian is still in line with her main objective to secure the services of world best footballers around the globe and have issued serious ominous transfer warnings to the likes of Real Madrid and Barcelona.According to the owner of the club they are still working to bring Diego Costa to the club.The Spain international was heavily linked with a move to China's lucrative top flight in January but decided to stay at Stamford Bridge.There are some reports in England claiming that the 28-year-old has been offered a staggering £650,000-per-week contract to tempt him to move to the CSL at the end of the European season. Shu Yuhui, the billionaire owner of Tianjin, has now claimed that a deal for Costa is in the pipeline and has vowed that the club will challenge the likes of Real Madrid and Bayern Munich for the world's best players in the transfer window."I can only say that we are still working on the deal [to sign Costa]. And we have already made contacts with several players," he told Sina Sports. "We have high standards [in buying foreign players] and those players prefer top clubs such as Bayern Munich and Real Madrid. It's safe to say that we have the same transfer targets as those illustrious clubs. "We may have to pay bigger price because our club are now competing with Real Madrid and Bayern Munich."