Paul Pogba and defenders Eric Bailly, Chris Smalling and Phil Jones all trained on the eve of Manchester United's Europa League semifinal first leg at Celta Vigo on Thursday.

England pair Smalling and Jones have been out since mid-March, while fellow centre-back Bailly limped off in the 61st minute of United's 1-1 draw with Swansea City on Sunday.

With left-back Luke Shaw sustaining a foot injury in the same game, United were facing a defensive injury crisis, but manager Jose Mourinho may now have more options at his disposal than anticipated.

Record signing Pogba's return to the training pitch at United's Carrington base west of Manchester will also be welcome after he missed their last two games with muscle fatigue.

Mourinho has been critical of Smalling and Jones for not being prepared to play through the pain barrier. It is unclear whether either they or Bailly will be fit to start in Vigo on Thursday.

Defender Marcos Rojo and striker Zlatan Ibrahimovic are out after both sustained knee ligament damage during United's quarter-final success against Anderlecht last month.

Midfielder Juan Mata could make his first appearance since groin injury, while Marouane Fellaini is available despite currently serving a three-game domestic suspension.

Meanwhile, Celta Vigo face one of the biggest nights in their history when they entertain Manchester United in the first leg of their Europa League football semifinal on Thursday.

The Spanish side have been preparing for the game since defeating Genk in the quarterfinals with coach Eduardo Berizzo carrying out a series of squad rotations to ensure his strongest starting XI, reports Xinhua news agency.

The rotations have seen Celta lose their last three home games in La Liga, with a 0-3 home defeat to Athletic Club Bilbao on Sunday, the latest of those setbacks, but striker John Guidetti is confident things will be different on Thursday.

"With the mentality we have built here, nothing is impossible," he told UEFA.com "We may be a small club and a team that others don't take much notice of, but we also know how good we are, that's why we've beaten Barcelona two years in a row and why we knocked Real Madrid out of this season's Cup. We have shown that we are a good team," insisted the Swedish forward.

Celta's league form may have drifted as they have focused their attention on Europe in the second half of the season, but their rivals are not in great form at the moment either.

Sunday saw Manchester United produce another flat display as they were held 1-1 by relegation threatened Swansea City and the side coached by Jose Mourinho is without a series of key players.

Zlatan Ibrahimovic is out for months after undergoing a knee operation, while they have a crisis in defense with Chris Smalling, Phil Jones, Marcos Rojo and Timothy Fosu-Mensah all out, while Eric Baily limped out of Sunday's game before halftime.

The good news for Mourinho is that Paul Pogba should be able to play after recovering from a hamstring injury.

Manchester United are struggling for a top-four finish in the Premier League, but both they and Celta know the prize for the Europa League winner is direct qualification for next season's Champions League, something that would mean both of their seasons were a success.