BARCELONA, Spain (AP) -- Lionel Messi is a doubt for Barcelona's next Spanish league match at Real Betis on Sunday after hurting his left knee in the Champions League.
The Argentine needs only one goal to match Gerd Mueller's 40-year-old record of 85 goals in a single year. Instead of making history on Wednesday, Messi was carried off with a bruised left knee after colliding with the Benfica goalkeeper.
Messi said on Thursday he was doubtful for the trip to play a Betis side that has climbed into fourth place after winning its last two games, including a victory over Real Madrid.
"I feel fine. Luckily it was only a knock," Messi said after doing gym work alone while his teammates practiced. "I feel much better than yesterday. I don't know if I will be there on Sunday. It depends on how (my knee) progresses."
Madrid faces what could be a tougher-than-expected test at Valladolid on Saturday.
Barcelona coach Tito Vilanova defended his decision to send on Messi with 30 minutes to go even when his team didn't need a result and was fielding youth team players.
"We had talked about the possibility of him playing half an hour," Vilanova said. "(Messi) is a player who likes to play. We didn't do it for the record like everyone is talking about. If we had wanted him to get the record, he would have played against Alaves (in the Copa del Rey) and the whole game (against Benfica)."
Vilanova said that playing 30 minutes in the match was the equivalent of "a good practice session."
"If we were worried about Messi getting injured, we would take him out of any game we are winning 3-0, and we never do that," Vilanova said. "If I had to do it again, I would make the same decision."
Under its first-year coach, Barcelona has established a Spanish league record for a best start to the season with 13 wins and a draw.
Messi's league-high 21 goals have played a major part in setting that milestone. The 25-year-old Argentina international hasn't missed a game because of injury since September 2010.
Betis has won three of its last four games at Benito Villamarin Stadium.
Led by striker Ruben Castro and midfielder Benat Etxebarria, Betis' attacking approach always leads to goals, for one team or the other. Only three teams have scored more than Betis' 23, and only three teams have conceded more than Betis' 24.
Castro has eight goals after scoring twice last weekend at Deportivo La Coruna.
"We are heading into the game with the idea of trying to win points," Betis midfielder Ruben Perez said. "It will be difficult because Barcelona is the best team in the world. They control the ball the entire game."
Atletico Madrid will try to rebound from yet another disappointing loss to Madrid in the last round when it hosts struggling Deportivo on Sunday. The team is six points behind Barcelona in second place and five points ahead of Madrid, which is in third.
Madrid enters Saturday's game after a pair of commanding home wins this past week featuring an in-form Cristiano Ronaldo. The Portugal forward scored both in Madrid's win over Atletico in the league and its victory over Ajax in the Champions League.
Madrid, however, will need to avoid another slip-up on the road if it hopes to retain any chance of catching Barcelona.
Madrid lost its last away game at Betis 1-0 and has as many defeats (three) as wins away from Santiago Bernabeu Stadium this season.
"It's going to be a tough game," Madrid goalkeeper Iker Casillas said. "Valladolid is playing very good football and just got a good win at Sevilla. They'll make things hard for us.
"It's a shame that we are so far behind Atletico even after beating them, and Barcelona is even farther ahead. We can't afford to drop any more points in the league."
Promoted Valladolid is having a strong return to Spain's top division. The modest club is in seventh place - one point from a Europa League spot - after winning its last two matches.
Coached by former player Miroslav Djukic, Valladolid has an entertaining attack led by forward Oscar Gonzalez and his team-high seven goals in league play. The team has lost only once in seven home games.
Angola striker Manucho provides a big target up front, while German forward Patrick Ebert gives Valladolid power to complement Oscar's finesse.
"Of course we can beat Real Madrid," Oscar said. "We will go out to play them as equals."
Also on Saturday, Real Sociedad will host Getafe in a meeting of two of the league's most attractive attacking sides which are both on winning steaks. Ernesto Valverde will coach his first Spanish league game with Valencia as it hosts Osasuna, while fifth-place Malaga hosts a slumping Granada.
Last-place Espanyol hosts Sevilla on Friday to open the round. Also on Sunday, Levante hosts Mallorca, while Celta Vigo is at Athletic Bilbao. Rayo Vallecano plays Real Zaragoza on Monday.