After beating Fluminense 2-0 yesterday, Chelsea has secured themselves a spot in the final of the FIFA Club World Cup and will face PSG on Sunday.
They will not be a favourite, but even if they lose, getting this far in the competition will bring a lot of extra money to the club, which they might decide to invest in top players, to further strengthen the squad and enable them to maybe compete for winning the Premier League instead of just fighting for the top 5.
A quick search tells me that, for the runner-up position, they would be getting a total of around $120 million, whereas for winning the cup, they could earn up to $155 million.

I don't see them having much chance against PSG though. The French club seems unstoppable this season.