Defending champions Atletico Madrid will find it “very difficult” to stop Real Madrid or Barcelona regaining the Spanish title, says boss Diego Simeone.
Atletico clinched their first La Liga since 1996 after a 1-1 draw at Barca on the final day of last season.
They have since lost several key men but beat Real in the Spanish Super Cup.
“Over one or two games we all have a chance. Over a full year you need to do things extraordinarily well, at 110% like we did last year,” said Simeone.
Atletico begin their title defence with the short trip to Madrid neighbours Rayo Vallecano on Monday.
Los Rojiblancos won the title by finishing three points ahead of illustrious rivals Barca and Real, but were denied a La Liga and Champions League double when they lost 4-1 to their cross-city rivals in the European final.
Over the summer they have sold both strikerDiego Costa, who scored 27 league goals last season, and left-back Filipe Luis to Chelsea, while goalkeeper Thibaut Courtois returned to the Premier League club after a two-year loan spell.
Both Real and Barcelona have spent over £100m on new players this summer, leaving Simeone to admit that Atletico are “in a different league” to their rivals.
However, a new-look Atletico lifted the two-legged Super Cup – Spain’s traditional season opener – with a 2-1 aggregate victory over Real this week.
Croatia striker Mario Mandzukic, who scored Atletico’s decisive goal at the Vicente Calderon, is expected to make his league debut on Monday, along with France attacker Antoine Griezmann and ex-Getafe goalkeeper Miguel Angel Moya.
“In a league of 38 games, the same Barca, having a bad season according to all the experts, nearly ended up champions,” said Simeone, who will watch the game from the stands after being sent off in Friday’s second leg against Real.
“Madrid too had a bad start to the season and if they had beaten Valencia at home four games from the end they would have been top.
“It is very difficult to fight over so many games, but in one match we are competitive and capable of beating anyone.”