The Catalans bounced back from two goals down to salvage a draw against Valencia at the Camp Nou, thanks to goals from Messi either side of half-time.
The Argentine forward was eventually able to finish the game, but he will now undergo tests to determine the severity of the injury.
However, it was not without cost as he needed treatment for what appeared to be a dead leg shortly after equalising and coach Ernesto Valverde... "Leo didn't ask me to sub him off". "We hope he can recover, just like the others". "I don't know too much more".
Barca beat Madrid 5-1 in the league earlier this season with Messi missing through injury, but he once again demonstrated his importance against Valencia.
Kevin Gameiro gave Valencia the lead on 24 minutes before Dani Parejo doubled the advantage from the penalty spot after Sergi Roberto bundled over Daniel Wass in the area.
Discovery of 'living fossil' galaxy could unlock secrets about early universe
Dwarf spheroidal galaxies are defined by their small size, low-luminosity, lack of dust and old stellar populations . The team published their discovery January 31, in the Monthly Notices of the Royal Astronomical Society: Letters .
"Between tomorrow and the day afterwards we'll need to see exactly how he is and what he has", Valverde said.
"But we have taken charge of the game from there".
"We did not play well in the first half but then we showed our character and we dominated", said Barca midfielder Ivan Rakitic. "It was a good reaction in the end but when you don't win you always feel that something has slipped away".
The draw presented Atletico Madrid, playing on Sunday, the chance to close the gap at the top to three points.
As well as Messi, there are also doubts about Ousmane Dembele's availability for the game. Second-placed Mbappé has 18 league goals (36 points) to his name, while third-placed Cristiano Ronaldo of Juventus, who also netted two goals last weekend, has 17 league goals (34 points).