Villarreal's Spanish league title credentials will be tested when it plays at defending champion Barcelona this weekend, while Spanish leader Real Madrid is at Sporting Gijon.
Third-place Villarreal's impressive start has it on the heels of the leaders, sitting three points adrift of Madrid and two off Barcelona after 10 games.
But Saturday's match at the Camp Nou offers the best test of whether or not the "Yellow Submarine" can prevent the title race from coming down to a Barca-Madrid fight for the fourth straight season.
Villarreal has strikers Giuseppe Rossi, Nilmar and Jozy Altidore in goal-scoring form, but it could be without defensive midfielder Marcos Senna through injury.
Barcelona will miss injured defender Gabriel Milito for four to six weeks after the Argentina defender tore a right leg muscle in Wednesday's 5-1 Copa del Rey win over Ceuta.
Even though the Spanish champion cruised past its third-tier cup opponent, coach Pep Guardiola showed the Catalan club was not prepared to ease up, bringing on Lionel Messi on as a second-half substitute.
"He didn't train (on Wednesday) and he said he wanted to play awhile," Guardiola explained after Messi scored his 17th goal of the season. "He likes to play and he said he wanted to."
Barcelona is likely without defender Gerard Pique (suspension) but welcomes back a healthy crop of rested players that includes striker David Villa, and midfield pair Andres Iniesta and Xavi Hernandez after they were rested against Ceuta.
Villarreal has won two, drawn two and lost one of its five road games so far, while Barcelona has won three of its five at the Camp Nou with a single defeat.
Real Madrid coach Jose Mourinho will not be on the touchline at El Molinon stadium after being sent off during Madrid's 5-1 cup win over Murcia on Wednesday.
The Portuguese coach doesn't expect that to impact his team's so-far unbeaten start.
"I don't play, the players do," Mourinho said shortly after Madrid exorcised its domestic cup demons by finally getting past a third-tier club after humiliating losses to Real Union and Alcorcon in the previous two seasons.
Striker Karim Benzema continued his excellent recent form and scored a penalty, while Madrid's fringe players also showed they could be counted on as the club faces a season-long task of juggling commitments in the league, cup and Europe.
"This team plays every game like it's the last," director general Jorge Valdano commented.
That's bad news for the rest of the league as Espanyol is the next closest to Madrid - eight points behind in fourth.
Title hopefuls Valencia, Sevilla and Atletico Madrid are already slipping too far behind.
"The Spanish championship does present surprises, so if you expect a different type of league you're likely living in a utopian world," Atletico coach Quique Sanchez Flores said ahead of his team's match against Osasuna, when it looks to overturn a three-game winless run. "You're dreaming if you think anyone else but Madrid or Barca will be champion."
In Sunday's other 11th round of games, it's: Zaragoza vs. Sevilla; Hercules vs. Real Sociedad; Racing Santander vs. Espanyol; Malaga vs. Levante; Mallorca vs. Deportivo La Coruna; and Valencia vs. Getafe.
Athletic Bilbao plays Almeria on Saturday.
