Tottenham Hotspur will host Chelsea in a blockbuster London derby in the 2020-21 Premier League on Friday.While the hosts have struggled for form in recent weeks, Chelsea are slowly starting to build a bit of momentum under their new manager Thomas Tuchel.The two sides played out an uninspiring goalless draw in their first Premier League meeting of the season. But under a more proactive manager like Tuchel at the helm, things could pan out differently this time.Chelsea are hitting form at the right time, so Mourinho will hope that his Tottenham Hotspur team can also up the ante.On that note, let’s take a look at five players to watch out for when Tottenham Hotspur will lock horns with Chelsea:#1 Son Heung-Min (Tottenham Hotspur)Son Heung-MinThere is added pressure on Tottenham Hotspur attacker Son Heung-Min after Harry Kane’s injury; the South Korean is expected to be the biggest threat against Chelsea.Son will miss his chemistry with Kane of course, but he is still a pretty good player in his own right. He will need to provide the drive and energy to the Tottenham Hotspur attack that they have been lacking in recent times.The north London side were the second-best team by far against Brighton, but their attack looked lacklustre, as they rarely tested the Brighton goalkeeper.Nevertheless, Son’s numbers this season have been impressive, as he has scored 12 goals and is the most creative Tottenham Hotspur player, having made more key passes than anyone else.With Chelsea not defending at their best this season, an in-form Son Heung-Min could cause Tuchel’s side a few problems.Most goals + assists in the Premier League this season: 🏴󠁧󠁢󠁥󠁮󠁧󠁿 Harry Kane (23) 🇵🇹 Bruno Fernandes (18) 🇪🇬 Mohamed Salah (18) 🇰🇷 Heung-Min Son (18) 🏴󠁧󠁢󠁥󠁮󠁧󠁿 Jamie Vardy (16) 🏴󠁧󠁢󠁥󠁮󠁧󠁿 Patrick Bamford (15)🏴󠁧󠁢󠁥󠁮󠁧󠁿 Jack Grealish (15)🏴󠁧󠁢󠁥󠁮󠁧󠁿 Callum Wilson (14) | #THFC | #MUFC | #LFC | #PL | pic.twitter.com/kBqleBH3H1— EPL Statman (@EPLStatman) February 2, 2021#2 Timo Werner (Chelsea)Timo Werner will have to discover his scoring boots against Tottenham Hotspur.Timo Werner’s goal drought in the Premier League has been a rather long one, but with Tuchel at the helm, the former Leipzig man will look to rediscover his scoring touch.Werner may not have scored against Burnley, where Chelsea ran away comfortable 2-0 winners, but his link-up play was impressive against the Clarets.Thomas Tuchel on Timo Werner: "Right now it’s important to rebuild his trust in himself and to find a smile on his face and stop doubting too much. It’s my job to do this." 😬Can he do it? pic.twitter.com/Jjzh9100QU— Goal India (@Goal_India) January 30, 2021The German's presence could be a factor against Tottenham Hotspur, considering the Lilywhites sit deep. Even though Werner may not have space to attack and use his pace, his clever footwork and link-up play could be crucial on Friday.