Real Madrid's defense of its Spanish league title has a tough opening test at home against Valencia on Sunday, while main rival Barcelona welcomes Real Sociedad to Camp Nou to mark the debut of coach Tito Vilanova.
Valencia held Madrid to a scoreless draw last spring at Santiago Bernabeu stadium, and Madrid coach Jose Mourinho will want to avoid any stumbles to start a season that promises to be a two-team duel with Barcelona as always.
"We know that every game in the league is important, and the first one is even more so," Madrid midfielder Xabi Alonso said. "These games demand you give 100 percent, and from the very beginning we have to play our best."
Madrid has kept the same squad that set league records for points (100) and goals scored (121) en route to deposing Barcelona last season. Only defender Pepe is doubtful for the opener, due to an ankle injury.
Mauricio Pellegrino will coaching debut for Valencia, which former manager Unai Emery guided to three consecutive third-place finishes but was let go after an irregular finish last season.
Valencia will try and make the most of its conditioning advantage, with the bulk of Madrid's squad recently returning from midweek commitments with their national sides.
Striker Roberto Soldado was back in practice for Valencia after missing the preseason because of a muscle tear in his right leg, but he is still questionable for the game. If he fails to play, his absence could mean Nelson Valdez will receive some playing time, along with fellow new signings Andres Guardado and former Madrid midfielder Fernando Gago.
"I believe we can get a good result Sunday," said forward Sofiane Feghouli, one of Valencia's standout players last season. "We have been working well and doing what our coach wants. The team is in good form, mentally strong. Now we have to take what we are doing in practice and bring it to the match."
In Barcelona, all eyes will be on Vilanova as he manages his first official game after five seasons as Pep Guardiola's trusted assistant.
"The team has arrived to the league opener in good shape," Vilanova said.
The match could also feature the long-awaited return of Spain striker David Villa for the Catalan club. Villa played his first minutes in a recent preseason match since breaking his leg at the Club World Cup last December.
Villa was still cautiously optimistic about his return.
"I feel like a football player again," Villa said after the match last Saturday. "I have to be patient. I have taken a big step forward, but I have to remember that I still have a long way to go. My goal is to play at the same level as before, but I don't know if I'll be able to yet."
Barcelona's chances of reclaiming the title from Madrid will largely hinge on the team's attacking players, Villa included, sharing the scoring burden with Lionel Messi, whose league-record 50 goals last season were still not enough to wrest the title from Madrid, which was helped by Cristiano Ronaldo's 46 league goals.
Real Sociedad caught Barcelona off guard in the second round last season to come from behind and draw 2-2 in San Sebastian. The Basque side has kept its group of speedy forwards in Carlos Vela and Antoine Griezmann while adding Chori Castro from Mallorca and defender Jose Angel, on loan from Roma.
"We knew when preparing for the game that we will not have the ball," Griezmann said. "We have to keep our lines tight and when we do have the ball, strike quickly. We want to get a good result, but it will be difficult. The key will be keeping alive our chances until the end, feeling we are in the match and not letting it get out of hand, scoring a goal when we have the chance and playing good defense."
Also on Sunday, Athletic Bilbao hosts Real Betis in a clash of two of the league's most exciting attacks from last season, while Atletico Madrid is at Levante in a meeting of last season's fifth- and sixth-place finishers.
The Spanish league gets under way on Saturday with promoted side Celta hosting Malaga, whose financial problems have forced it to sell playmaker Santi Cazorla to Arsenal and striker Jose Rondon to Rubin Kazan.
After the opening match, Sevilla welcomes Getafe before Espanyol travels to Mallorca.
On Monday, Deportivo La Coruna marks its return to the topflight after a one-season absence by hosting Osasuna. Granada is at Rayo Vallecano, and Zaragoza visits promoted Valladolid.