Boss Sam Allardyce is believed to covering his options amid fears Rovers may still lose Roque Santa Cruz before the transfer window closes on Monday.

With 28 goals in 51 games for Zenit, including one in the 2-1 UEFA Super Cup victory over Manchester United in August, Pogrebnyak would represent an ideal replacement for Santa Cruz.

According to Zenit president Maxim Mitrofanov, Rovers have made an offer close to the Russian club's valuation of the 25-year-old.

"Talks are in progress, but we have only received an unofficial offer from Blackburn and we are waiting for the official papers," Mitrofanov told the Russian media.

"Yesterday, Blackburn officials contacted us and made an offer for Pogrebnyak. It is almost the same as our valuation.

"If they send us the offer officially in time, we will contact Pogrebnyak and will persuade him to go to England.

"Blackburn have 48 hours to send us a fax with the official offer."

However, Mitrofanov concedes there may yet be a stumbling block.

"Pavel hasn't played 75% of the games for the national team to attain the necessary work permit to go to England," he warned.

"But Blackburn's officials will try to get him as an exception, stating that he was the top-scoring striker in last season's UEFA Cup."