Barcelona's soccer player Lionel Messi poses for photograph after receiving the Golden Boot trophey during an award ceremony in Barcelona, November 20, 2013. Messi won the trophy for scoring 46 goals in Europe's domestic leagues last season. [Photo/icpress.cn]

MADRID -- Lionel Messi, the four-time world player of the year, will be ruled out for the rest of the year due to a hamstring injury, said Barcelona coach Gerardo Martino on Monday.

Barcelona will have a Champions League clash with Ajax on Tuesday and  Messi scored a hat-trick in Barca's 4-0 win when the two sides last met in September.

Martino recognized Messi's absence will be a boost for any side that face Barcelona between now and his return.

However, he was still confident that Barca will get at least a point they need to guarantee first place in Group H.

"I have said already this week that without Messi we have lost the best player in the world and that always creates a difficulty. If I was on the other side I would see it as a positive, but the quality of the Barcelona squad means there can be no excuses," he said.