By Simon Evans
PORTO, Portugal (Reuters) - Manchester City face Chelsea in the Champions League final on Saturday. Here are five key tactical battles to watch out for:
WILL CHELSEA'S WING-BACKS BE ABLE TO ATTACK?
Thomas Tuchel's system at Chelsea has been designed to give licence to the wing backs to attack, whether it be Cesar Azpilicueta or Reece James on the right and Ben Chilwell or Marcos Alonso on the left, the German has players who are effective in transition and provide width.
The tricky factor against City is that Pep Guardiola always plays with two wide attackers, probably Riyad Mahrez on the right and Phil Foden or Raheem Sterling on the left, and their threat is so great that the Chelsea wing backs may find themselves with restricted opportunities to get forward.
If that happens then the "inside forwards", Mason Mount and Christian Pulisic, could find themselves more isolated than usual.
Tuchel is a coach who is always willing to adjust his formation and personnel to cope with the opposition and he has recently doubled up with Azpilicueta and James on the right -- -- a move that might help cope with the threat on the left.
CAN CHELSEA STOP DE BRUYNE?
Tuchel has shown in Chelsea's two recent victories over City that he can set up his team to effectively cope with their system but there is only so much that tactics can do to stop a player as brilliant as Kevin De Bruyne.
If the Belgian gets space, his ability to run at the defence and shoot from distance is a clear and obvious danger. Even when restricted, his passing range makes him a constant threat -- whether it be with through balls or sweeping passes out to the wide players.
Chelsea's two holding midfielders N'Golo Kante and Jorginho certainly have the capacity to limit De Bruyne -- if they don't Chelsea could be in trouble.
A FALSE NINE v THREE CENTRAL DEFENDERS?
Although Guardiola has two excellent centre forwards in club record scorer Sergio Aguero and Brazilian Gabriel Jesus, he has increasingly favoured playing with a midfielder given the main central role -- the "false nine" system.
Bernardo Silva is the most likely candidate for that position and if City do go down that route, it could leave Chelsea with the classic dilemma that faces teams up against the false nine: do you ask your central defenders to move out and shadow Silva or do you expect holding midfielders to take care of him and leave the back-line to sweep up behind?
WILL WALKER SIT OR PUSH?
In the first half of the semi-final first-leg against Paris St Germain, right back Kyle Walker was clearly under instructions not to advance forward and leave space behind him.
City were noticeably less dominant in midfield and attack without the England international doubling up with Mahrez on the right flank and the game -- and tie -- shifted after the break when Walker was back to his usual marauding self.
With Chilwell and Mason Mount likely to feature down the left attack for Chelsea, there may be a temptation for Walker to stick with his defensive duties. That might prove to be wise but it will surely come at a cost to City's options going forward.
WILL CHELSEA HAVE A CENTRAL THREAT?
Timo Werner's 12 goals in 51 appearances in all competitions hasn't been the return Chelsea were hoping for from a 50 million-pound striker.
The German was on target in the semi-final second leg against Real Madrid but that goal ended a run of seven straight Champions League games without one.
City have conceded just four goals throughout their entire Champions League campaign and Ruben Dias and John Stones have been excellent in the centre of defence.
So chances will likely be at a premium -- they will need Werner to make the most of whatever openings he gets.
(Reporting by Simon Evans, editing by Ed Osmond)