John Terry has been left devastated by Chelsea letting Antonio Rudiger leave the club at the end of the season, with the Blues legend voicing his frustration on social media.
Rudiger has been a key member of Chelsea's squad since his £29 million ($37m) move to Stamford Bridge from Roma in July 2017, racking up 196 appearances for the club in all competitions.
The 29-year-old has won five trophies in west London to date, including UEFA Super Cup and FIFA Club World Cup honours this season, but will move on to a new challenge when his contract expires in June.
Why is Rudiger leaving Chelsea?
Chelsea had been working to try and tie Rudiger to a new deal, but negotiations stalled due to the uncertainty surrounding the club's ownership.
Roman Abramovich put the club up for sale after he was hit with sanctions amid Russia's military invasion of Ukraine, and the UK government are working alongside Blues officials to find a buyer, but Rudiger wasn't willing to wait to decide his future.
Tuchel confirmed this after Chelsea's 1-0 win against West Ham on Sunday, telling reporters: "The situation is that he wants to leave the club. He informed me of this in a private talk.
"We gave everything - me and the club - but we could not fight anymore because of the actions.
"Without the sanctions we would at least be able to carry on fighting, but our hands are tied. We don't take it personally. It is his decision."
What has Terry said about Rudiger?
Terry has questioned Chelsea's decision to let Rudiger leave while suggesting Tuchel is losing one of the most important members of his team.
The Blues legend let his feelings be known in response to a Sky Sports post on Instagram.
"How have we let this man go," Terry replied in the comments section.
Rudiger bound for Real Madrid
Manchester United enquired about a potential deal for Rudiger after it became apparent that he might leave Chelsea at the end of the season, while Barcelona also expressed interest in his services.
Real Madrid appear to have won the race for his signature, with GOAL confirming on Monday that the Germany international has verbally agreed on a move to Santiago Bernabeu.
Rudiger is in advanced talks to sign a four-year deal with Madrid that will see him pocket around £200,000 in weekly wages.