The 25-year-old Spaniard agreed an initial three-year deal with the Whites last summer after moving to Craven Cottage from Rayo Vallecano.
However, he has not made a first-team appearance for the Championship club since October.
Celta are ninth in La Liga and will face Ukrainian side Shakhtar Donetsk in the last 32 of the Europa League.
Find all the latest football transfers on our dedicated page or visit our Premier League tracker here.

Chay Roberts-Jones was working at Blundells School at Tiverton, Devon, when he assaulted the girl under the guise of giving her a sports massage.
Roberts-Jones, 29, was cleared of sexually assaulting two other girls at a summer ball and a camping trip by a jury in February at Exeter Crown Court.
He was a physics teacher at the Â£31,000 a year school but now lives in France.
The court heard details of the conviction are to be supplied to the French authorities to ensure Roberts-Jones, previously of Preston Street, Exeter, is not able to work with children again.
In May 2014, he offered to give his victim a massage after she suffered cramp but went on to lift her top and try to pull down her trousers.
Recorder Mr Philip Mott, QC said there was a "higher culpability because of the abuse of trust".
He said: "This was not just flirting and an error of judgment but a more determined effort to pursue your desire and overcome her resistance."
The judge said Roberts-Jones, who now teaches adults in France, had experienced "substantial punishment in terms of career, self image and place in society" and suspended his sentence for two years.
He ordered Roberts-Jones to pay Â£2,500 costs and sign on the sex offenders register.
Emily Cook, for the defence, said there was an "element of infatuation" with the victim which "got out of hand".

Shipments jumped 21.8% from a year earlier, boosted by strong demand from the US and South East Asia. Most analysts had expected a 15% rise.
Exports, which are a key driver of China's growth, have been hurt recently by a slowdown in its key markets.
Analysts said the data may be skewed due to the Lunar New Year, but added that the trend was that of a recovery.
"Exports in January and February were both quite strong. This shows a recovering trend," said Sun Chi, an economist at Daiwa in Hong Kong.
However, there was a big fall in imports, which declined 15.2% from a year earlier.
Analysts said that the Lunar New Year celebrations, during which factories and businesses in China are shut for days, played a key role in that decline.
Last year, the Lunar New Year was celebrated in January, while this year it was observed in February.
This meant that factories operated for fewer days in February this year than in 2012.
"Since the factories worked for a [lower] number of days, they imported far less raw materials than they would normally have done," said Dariusz Kowalczyk, senior economist with Credit Agricole CIB in Hong Kong.
"That is why you have to combine the data for January and February to see the real picture."
Mr Kowalczyk said that the combined data for the two months indicated a jump of 5.1% in imports from a year earlier.
He added that the the jump in exports for February might also have been much stronger if the factories had worked the usual number of days.
Fulham midfielder Jozabed has joined Spanish La Liga side Celta Vigo on loan until the end of the season.
[NEXT_CONCEPT]
A public school teacher who groped an 18-year-old girl has been given a nine-month suspended sentence.
[NEXT_CONCEPT]
Chinese exports rose more than expected in February, adding to optimism over a recovery in its economy.