Barca and PSG go head to head in the first leg of their round-of-16 tie, and neither club can afford to go out of the competition this early.
Koeman has been tasked with restoring Barca to their former glories, while Lionel Messi will be desperate to win the European Cup once more having last lifted the trophy back in 2015.
As for PSG, Thomas Tuchel’s sacking not long after last season’s run to the final makes it clear that nothing less than glory will do for Pochettino in Paris – but that is easier said than done against Barca.
Pochettino will also have to navigate the first leg without injured stars Neymar and Angel Di Maria, though Messi and Barca will have to be wary of World Cup winner Kylian Mbappe’s lightning pace.
With kick-off at 8pm GMT, follow the latest action on our live match blog.
Watch: Mbappe scores stunning goal
Here is that Mbappe strike in all its glory…
Half-time | Barcelona 1-1 PSG
The Champions League is back! That was, quite frankly, an incredible opening 45 minutes at the Camp Nou.
We’ve seen a brilliant Lionel Messi penalty, a stunning Kylian Mbappe finish, and plenty of chances for both sides – what more could you want?!
Let’s hope for more of the same after the break.
One minute of injury time.
Chance for Icardi!
44 mins: The striker rises to meet a corner unmarked at the near post, but doesn’t quite have the angle as he heads wide.
He could still come good, but PSG could have effectively had the tie wrapped up by now if he’d been on form.
42 mins: Gueye catches Busquets a bit late here. He doesn’t think it’s a foul, but it’s a silly challenge to make when he’s on a yellow – especially on a player like Busquets, who is no stranger to top-level antics.
Luckily for Gueye, he just gets a talking-to – but he may be subbed at half-time, you’d imagine.
39 mins: Cheeky corner from PSG here as they try to catch out ter Stegen at his near post, but Barca clear the danger.
Chance for Kean!
Kean spins with his back to goal and fires in a low half-volley from the edge of the area, but ter Stegen reads it well and parries behind for a corner. He’s been busy today!
Chance for Griezmann!
36 mins: Barca are so close to going ahead again as they break off PSG’s corner. Griezmann picks the ball up inside his own half on the left, and works his way towards the centre before cutting back onto his left foot… but he drags the ball just wide of Navas’ left-hand post! That’s two big chances for him now.
Busquets goes down in the box before the corner comes in, but the referee just tells the players to get on with it.
Save by ter Stegen!
34 mins: Kurzawa has the freedom of the left flank today. The left-back finds space inside the box to shoot low across ter Stegen, but the Barca keeper gets a great low left hand to the ball to tip the shot wide for a corner.