It is typical of Thomas Tuchel to give Pep Guardiola a problem he wasn't expecting.
Manchester City were aware that they could have to negotiate with Bayern Munich when they sent Joao Cancelo to Julian Nagelsmann's side in January with a high option to buy, but now Kyle Walker is the senior full-back likelier to head to the Allianz. While a Cancelo who burned his City bridges prepares to try to come back into the fold for pre-season, Walker has had talks with Bayern over a summer move and may soon be packing his bags.
This is not a headache City would have wanted, but is one their set-up makes inevitable. Contrary to myth, Guardiola does not have a huge squad but does have 14-16 players who could start anywhere so when they spend more time on the bench than they would like it is natural that they look elsewhere; it must have been hard for Walker to sit out the Champions League final, but he was also overlooked for much of the season before that.