Roman Abramovich has been sanctioned by the UK Government, plunging Chelsea's long-term future into doubt.
The billionaire's planned sale of the club will now be stalled, but could still go through provided the Government issues a licence.
Abramovich would have to prove he would not benefit from the sale to meet conditions of any potential licence.
The 55-year-old has pledged to donate all funds from a Chelsea sale into a new foundation to benefit victims of Russia's war in Ukraine.
And should the Blues owner be able to prove his plans to Government officials, the sale of the Stamford Bridge club could yet go ahead.
Chelsea will be subject to a transfer ban and be blocked from negotiating new contracts with current players, after all of Abramovich's UK assets were frozen.
Defenders Cesar Azpilicueta, Antonio Rudiger and Andreas Christensen are all out of contract at the end of the season, leaving the senior trio in a state of short-term limbo.
The club can now only spend £20,000 on travel for away matches, plunging their Champions League round of 16, second leg tie against Lille on Wednesday next, into doubt.
Chelsea FC will not be allowed to sell any more match tickets - only season ticket holders and those who bought individual tickets before 10 March can go to games for the foreseeable future.
In a statement, the club confirmed the sanctions and that they will be seeking changes to the licence under which they are operating so that the club can continue to function as normal.
The statement read: "Chelsea Football Club has been advised that its owner Roman Abramovich has been sanctioned by the UK Government.
"By virtue of his 100 per cent ownership of Chelsea FC plc and affiliated entities, Chelsea FC would normally be subject to the same sanctions regime as Mr Abramovich. However, the UK Government has issued a general licence that permits Chelsea FC to continue certain activities.We will fulfil our men's and women’s team fixtures today against Norwich and West Ham, respectively, and intend to engage in discussions with the UK Government regarding the scope of the licence.
"This will include seeking permission for the licence to be amended in order to allow the Club to operate as normal as possible. We will also be seeking guidance from the UK Government on the impact of these measures on the Chelsea Foundation and its important work in our communities.
"The club will update further when it is appropriate to do so."
Chelsea cannot sell any new tickets to supporters, but all tickets sold before 10 March will be honoured.
Season ticket holders can still attend matches unaffected, while refreshments can still be served at Stamford Bridge.
Chelsea matches can still be broadcast, while only existing club merchandise can be sold.
British billionaire Nick Candy was the latest high-profile business magnate to throw their hat into the ring for Chelsea's sale, amid a host of suitors for the Champions League holders.
Swiss tycoon Hansjorg Wyss and American investor Todd Boehly were also in the running, with more than 10 credible parties understood to have been compiling bids.
The Chelsea squad will continue to prepare for Thursday's Premier League clash at Norwich as normal, but everyone at the club will now set about examining the details of the current situation.
The club's main sponsor have confirmed the suspension of its sponsorship.
A Three spokesperson said: "In light of the government's recently announced sanctions, we have requested Chelsea Football Club temporarily suspend our sponsorship of the club, including the removal of our brand from shirts and around the stadium until further notice.
"We recognise that this decision will impact the many Chelsea fans who follow their team passionately. However, we feel that given the circumstances, and the Government sanction that is in place, it is the right thing to do.
"As a mobile network, the best way we can support the people of Ukraine is to ensure refugees arriving in the UK from the conflict and customers currently in Ukraine can stay connected to the people who matter to them.
"Therefore, we are offering connectivity packages to all Ukrainians arriving in the UK, and those in Ukraine."
