Chelsea will resume their campaign in Europe’s elite club competition when they travel to the Signal Iduna Park to take on Borussia Dortmund in the UEFA Champions League Round of 16 first leg on Wednesday (February 15).

The Blues have endured a poor run of form and are winless in their last three games. That’s in stark contrast to Dortmund, who have won their last seven. A major talking point ahead of the game remains Graham Potter’s squad selection. The Chelsea boss would’ve loved to select all the new signings in his 25-man Champions League squad, but UEFA rules do not allow that.

Rather, only three new January signings can be selected, which has forced Potter to go with Mykhaylo Mudryk, Enzo Fernandez and Joao Felix.

His decision means other January acquisitions David Datro Fofana, Noni Madueke and Benoit Badiashile won’t be playing a part in the Blues’ Champions League campaign this season. Among the three, Badiashile’s absence could be most acutely felt.

Badiashile has been one of Chelsea’s best players

Badiashile joined Chelsea from Monaco in a £35 million deal and has since established himself as one of the club’s best performers.

He may have arrived at a time when the Blues were enduring an injury crisis, with Kalidou Koulibaly and Wesley Fofana injured, but he has proved himself worthy of a starting spot.

The 21-year-old defender has also earned the trust of Potter and is now one of the first names on the team sheet in the Premier League. Badiashile’s partnership with Thiago Silva has delivered three clean sheets in four games, while Chelsea are yet to taste defeat when the duo have started together.

It’s no coincidence that Chelsea’s defensive record has improved tremendously since the young Frenchman arrived. Although he’s not a big-name signing, he has made a bigger impact than any of the other January arrivals.

Chelsea’s should’ve added Badiashile to their Champions League squad

Chelsea’s decision to not add Badiashile to their Champions League squad was expected, especially as he was competing for a place against Felix, Mudryk and record-signing Fernandez.

However, the Blues should’ve made room for the defender, considering how impactful he has become in the team. He has complemented Silva well, and his great passing allows the team to play out from the back.

That’s what Chelsea will miss in the Champions League. There’s not much Silva can do on his own if he doesn’t play alongside a player who makes up for the 38-year-old’s limitations.

Potter has never hidden his admiration for Badiashile and even praised him this week. telling

“He brings a calmness; he’s good with the ball; he’s left-footed, so he gives us balance on that side. Attacking and defending, he’s had a solid start for us. Young player, you never know when they come into the country in a different situation, but so far he’s managed it really well. He’s a nice person, a calm, humble guy who wants to work and wants to improve. The signs are good. He’s had a nice relationship with Thiago.”

When Chelsea step out for their game against Dortmund, they will feature a team with exciting attacking talent that cost more than £200 million. However, they’ve also left one of their best players out of their Champions League squad, which could come back to haunt them.