Barcelona and Madrid face uncertainty ahead of Spanish league season. Atletico could take advantage

MADRID (AP) — Barcelona couldn’t bring back Lionel Messi, and lost two other stalwarts in Sergio Busquets and Jordi Alba.

Real Madrid couldn’t sign Kylian Mbappé — so far at least — and saw veteran striker Karim Benzema leave for Saudi Arabia.

The Spanish league begins this week with the title favorites facing a transition year and squad changes that might open the door for other challengers.

Diego Simeone’s Atletico Madrid could be the team to take advantage after keeping most players in a squad that offered the best soccer in…