Messi, who twisted his right ankle during Barca's Champions League match away to Dynamo Kiev last week, missed their first training session in Abu Dhabi on Monday, staying in the hotel for treatment, the team said.
"He's fed up, but keen to recover and see if he can make it to the match," the European champions' captain Carles Puyol told reporters after the session.
Puyol said Barcelona were keen to round off a brilliant year with the world title that escaped them three years ago when they lost 1-0 to Internacional of Brazil in the final in Japan.
"The team have already made history but we want more, that's why we're here," said Puyol.
"We're keen and have a dream. We had the chance to win it and we let it slip. We hope that won't happen again."
Barcelona had a light session given that they had a long flight from home on Sunday, having won the city derby 1-0 against Espanyol on Saturday.
"We're used to playing lots of matches in a row with little time to rest," Puyol said as Barcelona prepared for a third match in eight days in three different competitions.
He said Mexican side Atlante were an attractive footballing side in a vein similar to Barcelona.
"They're a daring side who like to play the ball and they have quality players like Santiago Solari, who I know well having faced him before, and fast, skilful players up front," he said.
Solari played several times in the big Spanish "clasico" against Barcelona while he was at Real Madrid between 2000 and 2005.
South American champions Estudiantes of Argentina meet Asia's Pohang Steelers of South Korea in the first semi-final on Tuesday.
