Lionel Messi suffered another hamstring injury to sour Barcelona's 4-1 win over Real Betis on Sunday night.
Messi was forced off in the first half - the third time he has been hit by hamstring problems this season - with the club confirming on their Twitter feed during the match that he would undergo a scan on Monday.
On the pitch, goals from Neymar, Pedro and a Cesc Fabregas double sealed a win that moves Barca three points clear at the top of the Primera Division table after Atletico Madrid were held to a 1-1 draw by Villarreal.
Jorge Molina scored a 90th-minute penalty for Betis, who remain rock bottom to keep the pressure on coach Pepe Mel.
Fabregas has has urged Messi not to try and rush his recovery, saying: "He needs to take as much time as he needs, to recover and get back to his level. We need him at his best.
"I had something similar at Arsenal. You think you're okay, but you're not.
"I had this injury, I wasn't right for up to a year and half, it's a really frustrating injury. You need to take whatever time you need because if you don't it won't heal properly."
Atletico dropped points for just the second time this season at fourth-placed Villarreal.
A second-minute Mario Gaspar own goal gave the capital club the lead, but they duly handed it back when Juanfran turned the ball into the wrong goal 11 minutes from the end.
Sevilla halted a two-match losing streak with an impressive 3-1 victory at 10-man Espanyol.
Los Rojiblancos made an ideal start at the Estadi Cornella-El Prat as Federico Fazio and Machin Vitolo put them two goals to the good inside the first 10 minutes.
The home side's captain Sergio Garcia pulled one back midway through the first half but Carlos Bacca restored Sevilla's two-goal lead and it proved decisive.
Valencia twice came from behind to earn a 2-2 draw at home to Real Valladolid, but will consider it two points lost after dominating possession and missing an early penalty.
Ever Banega skied a spot-kick after five minutes and Javier Guerra then gave the visitors the lead against the run of play.
Dorlan Pabon equalised for Valencia just before the half-hour mark but Gilberto Alcaraz put Valladolid ahead again early in the second half. Sophiane Feghouli equalised on 76 minutes.