The Champions League knockout phase play-offs get under way this week as 16 teams face off looking to join the eight already into the last 16.

Manchester City and Celtic are among those aiming to progress from their two-legged ties - against European champions Real Madrid and Bayern Munich respectively.

But which teams are in the play-offs? And who is already through?

Manchester City came from behind to beat Club Brugge and squeeze into a place in the play-offs, while Aston Villa and Arsenal joined Liverpool - who had long booked their place - with automatic progression to the last 16.

Celtic, who lost 4-2 to Aston Villa in their final league game, join City in the play-offs - all five British teams progressed through the league phase.

These are the teams through to each stage:

Last 16: Liverpool, Barcelona, Arsenal, Inter Milan, Atletico Madrid, Bayer Leverkusen, Lille, Aston Villa.

Knockout phase play-offs: Atalanta, Borussia Dortmund, Real Madrid, Bayern Munich, AC Milan, PSV, Paris St-Germain, Benfica, Monaco, Brest, Feyenoord, Juventus, Celtic, Manchester City, Sporting, Club Brugge.

And we already have an idea of who could play who in the next rounds - with City and Celtic in particular about to face huge tests.

The full draw for the play-off round is as follows:

Brest v Paris St-Germain (first leg 11 February, second leg 19 February)

Juventus v PSV Eindhoven (first leg 11 February, second leg 19 February)

Manchester City v Real Madrid (first leg 11 February, second leg 19 February)

Sporting v Borussia Dortmund (first leg 11 February, second leg 19 February)

Club Brugge v Atalanta (first leg 12 February, second leg 18 February)

Celtic v Bayern Munich (first leg 12 February, second leg 18 February)

Feyenoord v AC Milan (first leg 12 February, second leg 18 February)

Monaco v Benfica (first leg 12 February, second leg 18 February)

Liverpool and Barcelona cannot meet until the final now after finishing in the top two of the league phase.

The Reds will play one of Monaco, Brest, PSG or Benfica in the last 16 - with Barca facing another of those teams.

Arsenal, who finished third, will play Feyenoord, Juventus, AC Milan or PSV.

Aston Villa, who just finished in the top eight after beating Celtic, will take on Sporting, Club Brugge, Atalanta or Borussia Dortmund.

Those ties will take place on 4-5 and 11-12 March.

But they will not know which team exactly until the last-16 draw takes place on 21 February.

Clubs will know their potential route to the final by then - with the draws for the quarters and semis also taking place that day.

There is a chance Liverpool and Aston Villa could meet in the quarter-finals if they both win their last-16 ties.

Arsenal could meet Celtic or Manchester City in that round too.

But all of those potential fixtures depend on which way the last-16 draw goes. It is also possible British teams could meet in the semis or final.

All should become clearer after 21 February when the draws for the last 16 onwards are made.