As sad a reality as it is for Borussia Dortmund, yet another of their champions has left the Ruhr based club for their rivals to the south, Bayern Munchen.

The fact that Mats Hummels was actually a Bayern Munchen junior will do nothing to ease the hurt for Dortmund fans, as the centre back had amassed almost 250 appearances for the club, and leaves as their now former captain.

Hummels is not the only first team mainstay to leave BVB this offseason, with Ilkay Gundogan saying his goodbyes before leaving to Manchester City to take up a position in Pep Guardiola's midfield.

Between Hummels and Gundogan's departure, there is a lot of defensive pressure to replace at the Westfalenstadion, and to make a dent in the UEFA Champions League next year, Dortmund will have to open the kitty.

Between replacements already at the club and quality CBs on the market, who is best served to come straight into the heart of the defence for the Yellow and Blacks?

Sven Bender

Sven Bender is probably the popular choice at the club to take over the former captain's spot in the lineup, and maybe even one of the leading choices to take over the captain's armband.

Bender's skill set means he is able to not only defend with the best of them, but can also float into the midfield if need be, which was not something Hummels was overly keen to do.

Matthias Ginter

Matthias Ginter is only 21 but has huge fans at the club, such as his potential. The young German prefers to play on the right side of the defence, but has the potential to play at cb, as well as a defensive midfielder.

With the many departures in the first team at positions Ginter can cover, it is likely he will see plenty of action for BVB this year. At cb or not is another story.

Neven Subotic

When he first signed with Dortmund, Neven Subotic featured heavily in the first team, and even partnered the departing Hummels in defence on many occasions.

Now with Hummels gone and Subotic reaching the peak years of his career, he would love to fight his way back into the side. His propensity for a headed goal may help his cause.

Aymeric Laporte

BVB only have around 30 million Euros to play with this offseason, meaning Aymeric Laporte is a shoot the moon prospect, but what a signing he would be to replace the departing captain.

Manchester City are keen on the 21 year old Frenchman, and his incumbent club Athletic Bilbao are desperate to keep him, but for a player of his age and ilk, he may favour a move to Germany as opposed to the spotlight of the EPL.