Stuart McCall has blamed Rangers' recent poor form on the January exit of young midfielder Lewis Macleod.
The 20-year-old left Ibrox to join Championship club Brentford for a fee believed to be £1m, after making 52 appearances for the club.
Rangers drew five Scottish Championship matches in a row before their 2-0 victory over Hibernian on Sunday.
"I think the key thing in January, if you look back at it, is [Hibernian] managed to bring in five players," McCall is quoted as saying by Here In The City.
"They brought the boy [Keith] Watson in from Dundee United, [Fraser] Fyvie, [Martin] Boyle from Dundee, [Franck] Dja Djédjé and managed to keep their best young talent in Scott Allan. Whereas if you look at ourselves we lost our best young talent in Lewis Macleod."
Rangers signed five players on loan from Newcastle United in January but only Haris Vuckic has made any impact at Ibrox.