By Iain Rogers
MADRID (Reuters) - When Lionel Messi was taken off on a stretcher with what looked like a serious knee injury on Wednesday it was a jolting reminder, if one were needed, of just how crucial the Argentine forward is to Barcelona's fortunes.
Thankfully for fans of the La Liga club and those who enjoy watching the Argentine World Player of the Year weave his magic, tests quickly ruled out anything worse than bruising, sustained in a collision with Benfica goalkeeper Artur near the end of the Champions League Group G game.
The prolific 25-year-old may be available for undefeated Barca's match at Real Betis on Sunday (2000 GMT) and if he plays he will have a chance to add to the 21 goals he has scored in 14 La Liga matches this season.
That represents almost half the club's total of 48 and has helped them win all but one of their matches and put them six clear of Atletico Madrid on 40 points at the top of the table.
He netted 50 of Barca's 114 La Liga goals last term and 31 of 95 during the 2010-11 campaign and he has been top scorer in the Champions League the past four seasons, when Barca twice won the title.
It is hard to imagine them without Messi, who last missed a game through injury in September 2010 after a crunching tackle from Atletico defender Tomas Ujfalusi damaged an ankle.
Favourite to secure a fourth consecutive World Player award when the winner is announced next month, he is involved in virtually every attack and typically the only thing on the minds of his team mates when they are going forward is to try to get the ball to him.
Barca were already through to the last 16 of Europe's elite club competition as group winners and coach Tito Vilanova was asked after the Benfica game why he had brought Messi off the bench for the final half an hour instead of resting him.
Vilanova said it had nothing to do with Gerd Mueller's 40-year-old record of 85 goals for a calendar year, which Messi is one short of on 84.
His two goals against Athletic Bilbao last weekend also made him Barca's joint top scorer in La Liga, level with Cesar Rodriguez on 190.
"If it happened again I would take the same decision as he could injure himself in training or at any time," Vilanova told a news conference.
"He is a player who likes playing and not because of the (Mueller) record that everyone is talking about ... it also serves as physical training," he added.
Barca travel to Seville to take on Betis with the Andalusian club still on a high after beating champions Real Madrid 1-0 at their Benito Villamarin stadium last month.
They won 3-2 at Deportivo La Coruna last weekend and are fourth on 25 points, four behind Real, who play at seventh-placed Real Valladolid on Saturday (1900).
Despite their impressive early-season form, Betis defender Ruben Perez said the club are still focused on securing their place in the top flight rather than thinking about a possible place in European competition next season.
"We have to carry on in the same vein but we have to be realistic and make sure of our place in the first division as soon as possible," Perez said on the club's website (www.realbetisbalompie.es).
"It's going to be a tough game because it's the best team in the world," he added.
"They have the ball for the whole match and it's difficult. We'll try to get at least a point or go for the win."
Atletico, who lost 2-0 at city rivals Real last weekend, are at home to Depor on Sunday (1800), while Ernesto Valverde will take charge of Valencia for the first time since replacing the sacked Mauricio Pellegrino when his new side play at Osasuna on Saturday (2100).
Valencia, through to the last 16 of the Champions League along with Barca, Real and Malaga, are 12th on 18 points.
Malaga, in fifth three points behind Betis, are at home to Andalusian neighbours Granada on Saturday (1700).
(Editing by Patrick Johnston)