Currently Arsenal has been the only team in England that I can say for sure may give PSG some tough time if they ever get to meet, their only problem will be with their mentality, I do not trust Chelsea to stop PSG from lifting the FIFA Club World Cup this time, except PSG suffers a bad day, Chelsea is not their match currently. I hope Chelsea use this to gain some experience be just incase they get to the finals again some other time but PSG is at their peak so we not expecting any less from them.
Of course, no one should expect much from Chelsea in this Club World Cup final unless PSG makes a fatal error that could cost them the match, which would be a surprise. But after seeing PSG's performance this time in the Club World Cup, it's pretty much impossible not to back PSG, as they have more strength than Chelsea. However, as for Arsenal, I think they also lack something besides mentality, namely a more lethal attack. In the Champions League, it's not just about mentality but also several other factors, such as defense and a more dangerous attack.