Centre-back Hummels, 27, is the third Dortmund star to join Bayern in three years after midfielder Mario Goetze left to join the Munich giants in 2013, followed by striker Robert Lewandowski in 2014.

“For the coming 2016/17 season, the Borussia Dortmund player Mats Julian Hummels will transfer to FC Bayern Munich,” said Dortmund in a terse statement.

“Both clubs have now reached an agreement in principle and the formal completion of the transfer, and the usual medical examination of the player, should be completed in the coming days.”

Reports in the German media say Bayern have paid up to 38 million euros (US$43.26m) for Hummels, who had a year left on his Dortmund contract.

Having left Bayern in 2009 for Dortmund, Hummels is returning to the Bavarian giants having won the German league title twice with Dortmund (in 2011 and 2012) and the German Cup (2012) before helping Germany win the 2014 World Cup in Brazil.

Bayern also announced on Tuesday the signing of teenage Portugal international Sanches from Benfica on a five-year contract, having beaten Manchester United to sign the teenager.

The Bavarian giants say they paid 35 million euros (US$39.81m),  plus possible bonuses, for the defensive midfielder, who was first capped by Portugal earlier this year having only made his debut for Benfica in the Portuguese league last October.

Social media has reacted quite positively to these surprise signings late into the season, join the conversation with us using #360Fans.