Although the winter transfer window has yet to open, the Premier League leaders have already reportedly made their first signing of 2015.

Although the winter transfer window is yet to open, reports claim that Chelsea have already secured their first signing of 2015.

The Blues have been in great form so far in the Premier League and have only lost one out of their 19 matches so far. As such, they currently sit on top of the table, three points ahead of last season's champions Manchester City, and despite enjoying the joint-highest scoring offense with 41 goals, Jose Mourinho is already looking to add some new faces to his attacking arsenal.

While not familiar to most fans, Andrej Kramaric has garnered the attention of the London giants due to his goal-scoring form with Rijeka in Croatia's top division. The 23-year-old has netted nearly 30 goals so far in all competitions, including 21 in 19 league appearances and has been linked to a host of other European sides, including fellow Premier League side Tottenham as well as Serie A trio Milan, Inter, and Juventus.

The Croatian international has earned attention from several European sides due to his prolific season thus far

However, reports indicate that it's the 2012 Champions League winners who have jumped ahead in the race to sign the young attacker and have apparently submitted a £7.5 million bid for him. Some reports claim that he has already agreed personal terms with Chelsea, whereas others claim that it's still something that has yet to be finalized.

As Chelsea currently have three senior strikers on their books it will be interesting to see as to whether the Croatian international will link up with his colleagues at Stamford Bridge or be sent out on loan to gain more experience.