Andres Iniesta and eight more Barcelona first-team players underwent blood and urine anti-doping tests on Thursday (8 March) with Ernesto Valverde's pupils continuing their preparations for a Saturday's [10 March[ trip to Malaga which will come only four day before the crucial Champions League visit of Chelsea.

Meanwhile, the availability of the captain for those two games remains uncertain after on the club said that the midfielder continued working on the recovery from a hamstring injury sustained during the weekend's 1-0 victory over Atletico Madrid.

Iniesta was forced off in the first-half of the clash with Diego Simeone's side due to the blow but the club have failed to set a timeframe on his recovery.

On Wednesday [7 March], morning Barcelona informed on their official website that his "availability for future matches will depend on how things develop" and the captain consequently was one of the many first-team absentees when his side beat Espanyol 4-2 on penalties to lift the Catalan Super Cup.

Lionel Messi, Luis Suarez, Philippe Coutinho, Marc Andre Ter Stegen, Ivan Rakitic, Sergio Busquets, Jordi Alba, Sergi Roberto, Gerard Pique, Samuel Umtiti, Paulinho and Thomas Vermalen also missed the derby with Valverde opting to rest the majority of his first-team players ahead of having them fresh for the next week's crucial visit of Chelsea, with the Catalans looking to capitalise on the 1-1 draw from the first leg to book a place in the quarter-finals.

Valverde's pupils returned to training on Thursday with some members of Fifa shopping on the Barcelona training ground to perform some drug test on Iniesta and cop.

"Fresh from their Supercopa de Catalunya win against Espanyol in Lleida, the FC Barcelona squad trained on Thursday morning on the Camp Tito Vilanova pitch at the Ciutat Esportiva, with all of the available first team players," the club informed in their official website.

Barça B's Carles Aleñá, who had featured in the starting XI on Wednesday night, also took part in the session to prepare the team for Saturday's meeting with Malaga at La Rosaleda.

FIFA sent representatives to the training session to undertake anti-doping tests on some players, collecting blood and urine from Sergio Busquets, Paulinho, Jordi Alba, Digne, Iniesta, Piqué, André Gomes, Ter Stegen and Vermaelen.

Barcelona didn't provide any fresh update regarding Iniesta's recovery but Denis Suarez missed the workout having been ruled out for between 15 and 20 days due to an "adductor muscle strain" suffered during the win over Espanyol.

Meanwhile, long-term absentee Nelson Semedo also remains on the sidelines with the Portugal international expected to be out of action until next month due to another hamstring blow suffered in the recent 6-1 victory over Girona.

Suarez and Semedo are thus ruled out for the coming games against Malaga and Chelsea with Iniesta facing a race against the time to be at least ready for the crucial clash with the Premier League champions.