Scottish Premier League officials have turned down Rangers' request to postpone Saturday's match against Dundee United.Rangers are scheduled to play eight games in 21 days, including the Uefa Cup final against Zenit St Petersburg.The Russian Football Federation have allowed Zenit to postpone four of their matches and take a two-week break to prepare for the final, but the SPL has refused to rearrange the Dundee United match at short notice.An SPL spokesman said: "We had a request from Rangers to have the Dundee United game postponed."Postponing that game would have a knock-on effect for the rest of the programme."We would have to move all the top-six fixtures to end the season with all the teams playing at the same time."Reports have suggested the Scottish Football Association would consider rearranging the Scottish Cup final between Rangers and Queen of the South, which is scheduled for May 24.But Queen of the South would object to a new date because fans from around the world have made plans to watch the biggest game in the club's history.