Levi Colwill is some player! Six things we learned as Chelsea lose Christopher Nkunku to injury in draw with Dortmund

It's the last thing anyone wants to see: a player down clutching his leg in a pre-season game. That was what we got midway through the first half, though, as Chelsea saw their new signing Nkunku go down with an injury.

The pitch conditions were at least partly to blame, adding even more frustration to the whole situation. The field looked to be a problem all night, so it just felt like an injury like this was on the cards.

Fortunately, it appears it isn't catastrophic. Nkunku was seen on the bench with an ice pack on his leg, a good sign, for sure. What it means for his immediate future is anyone's guess, though, with a season-opening clash with Liverpool just a week-and-a-half away.

While one striker target, Dusan Vlahovic, was scoring for Juventus against Real Madrid, another got a chance to prove himself in Chelsea blue. Nicolas Jackson has outperformed expectations so far this pre-season, and he was active here. The summer signing had several chances to score and, on another night on another pitch, he might have gotten one or two.

Still, despite the lack of goals on this night, Jackson looks the part. He'll need time to adjust to the Premier League, for sure, but if this pre-season is any indication, he'll probably be just fine.

Another striker may come in; this is Chelsea, after all. If one doesn't, though, and the club starts the season with Jackson leading the line, they'll be starting the season with a player that certainly brings something fresh and something new to an attack that has needed just that for some time.

Call it the new contract bounce. Colwill recently committed his future to Chelsea, despite plenty of rumours linking him with a move away, and the Blues will certainly be happy that he did based on this performance.

Starting next to Thiago Silva, Colwill was cool as can be, fitting in nicely right next to the Brazilian legend. Silva, of course, was steady as always, but it was Colwill that was the standout central defender.

His passing opens up so many things for Chelsea, with Colwill joining Silva with his ability to break lines out of the back. Defensively, he was reliable, too, going toe-to-toe with a strong Dortmund attack throughout.

He's only 20, but they do say if you're good enough, you're old enough. Well, Colwill looks plenty good enough to play a role this season and in the years to come with his future at Stamford Bridge now clear.

It hasn't been Raheem Sterling's best pre-season, to say the least. The England star has struggled mightily, and this may have been his worst performance yet.

Sterling was all over the place on Wednesday night, establishing himself as the place Chelsea attacks went to die. There was very little that Sterling did right, only continuing on a worrying trend that has defined his preseason.

The ex-Manchester City man is meant to be a veteran figurehead in the attack, but is instead being totally outperformed by just about everyone around him. And, with just a few days left before the start of the season, pre-season rust can't be an excuse.

With so many attackers in the squad, and maybe even a few more on the way, is Sterling's starting spot in danger? On this form, it has to be, right?

You could see the smile on his face as the ball soared over the line. What a moment for Burstow, Chelsea goalscorer.

The 19-year-old forward hasn't featured for the Blues in official competition, but he got their goal on Wednesday night. As Dortmund failed to clear a late set-piece, the ball fell to Burstow, who flicked on a difficult header into the back of the net to level the scoreline.

He'd only come on eight minutes prior, replacing Jackson after his busy shift. It'll likely be his last appearance for Chelsea this season, as he's been linked with both permanent and loan moves, but he's got a goal to his name now.

A hangover from last season? It doesn't seem so! For the second time this week, Dortmund went toe-to-toe with a Premier League giant and left with a decent result. Yes, it's pre-season, so there's only so much you can take away, but it's always better not to lose these games, isn't it?

It wasn't a pretty game, for sure, and it wasn't back and forth in the way their win over Manchester United was, but they can still take plenty of positives from it.

The world is interested in how Dortmund will approach this season. Mentally, it'll be hard to shake off what happened last campaign. Edin Terzic's side, though, look well on their way and ready to give Bayern another go.