MOSCOW -- Russia is trying to stop the retractable field at a World Cup stadium from shaking.
Deputy Prime Minister Vitaly Mutko said the field at the 68,000-seat stadium in St. Petersburg has been experiencing problems with the mechanism that allows it to be stored outside and wheeled in for games.
He denied it will cause further delays for the arena, which is due to host Confederations Cup games next summer and one of the World Cup semifinals in 2018.
"The issue is that the field rolls into the stadium on an unstable base and needs to be strengthened," Mutko said while visiting the stadium on Thursday in comments reported by local media, adding that the problem was "nothing unusual" and the stadium would still meet its completion date next month.
"An issue was identified with the pitch stabilisation" during an inspection by FIFA officials on Monday, football's world governing body said in an e-mailed statement.
"The authorities have acknowledged the challenges and it was agreed that engineers will shortly propose a solution to ensure a stable playing field. FIFA will monitor the situation."
Earlier, the deputy governor of St. Petersburg said FIFA inspectors also had concerns about access to the stadium and nearby training fields, Russian agency R-Sport reported.
The venue, which has been hit by repeated construction delays, allows the field to be stored outside and retracted for games, allowing the grass to grow better and avoid damage when non-sports events are held in the stadium.
Construction on the stadium, located on an island in the River Neva estuary, began a decade ago and has seen repeated delays and dramatic cost increases to around 43.8 billion rubles (€622 million). The company building the stadium was replaced earlier this year following a dispute with the city government.
As well as the shaking field, other problems related to the construction of the stadium have included embezzlement inquiries and the deaths of at least eight workers.