A former prima ballerina will serve as the Bolshoi Ballet's acting head, as its artistic director undergoes further surgery on Wednesday following an acid attack last week.

The famed Russian dance troupe has announced the appointment of former principal dancer Galina Stepanenko to the temporary role and offered an update on Sergei Filin, who suffered third-degree burns when a masked man threw sulphuric acid in his face last Thursday outside his Moscow home.

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Russia's Bolshoi Ballet has appointed former prima ballerina Galina Stepanenko, seen right at a rehearsal in 2001, its acting chief after the acid attack on artistic director Sergei Filin. (Alexander Nemenov/AFP/Getty Images)

Dancer Stepanenko, 46, had just retired from her performing career in December and was transitioning to a new role as an instructor with the troupe, which she joined in 1990. 

Bolshoi Theater general director Anatoly Iksanov told reporters that Filin was slated to undergo a second eye operation on Wednesday in an attempt to preserve his sight and that doctors would likely share a status update in 10-14 days.

Filin eager to return to Bolshoi

In an interview with Russian newspaper Komsomolskaya Pravda published Tuesday, the 42-year-old Filin seemed optimistic about his recovery and eager to return to work at the Bolshoi.

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Former Bolshoi dancer-turned-director Sergei Filin told a Russian newspaper he wasn't in bad spirits and that he was eager to return to work after his surgery and recovery. (Alexander Natruskin/Reuters)

"I am not in bad spirits," he told the paper, despite noting that the acid had reached his right eye and caused severe damage to his eye and his face.

An acclaimed former Bolshoi dancer, Filin said that the acid attack had actually been less painful than the time he forced himself to dance Swan Lake on a broken leg because he didn't want to disappoint his mother, who was sitting in the front row.

He ended his performing career in 2007 and was appointed Bolshoi Ballet artistic director in 2011, after serving the same role at Moscow's Stanislavsky and Nemirovich-Danchenko Theatre.

Threatened, targeted for weeks

Filin had received threats and been the target of various incidents — including having his car tires slashed, email account hacked and personal correspondence made public — in the weeks before the attack. He told the paper he was rebuffed in December when he asked his superiors for protection.

The attack has shocked the Russian arts community, some of whom attributed it to infighting and accusations of favouritism at the venerable company, which dates back to the 18th century.

Closed circuit footage captured near the crime scene showed the suspected attacker fleeing through an outdoor parking lot. Moscow police are continuing their investigation.