Mark Warburton's side currently sit five points clear at the top of the table.
Stuart McCall believes that Rangers will still secure promotion back to the Premiership as winners of the Scottish Championship this season, even if they fail to make any new signings before the window shuts, the Evening Times reports.
The Light Blues have failed in their bid to sign Toumani Diagouraga - who has instead joined Leeds United - and have, so far, had no luck in completing a deal to sign St Johnstone forward Michael O'Halloran (via Evening Times).
Despite the recent difficulties in getting deals across the line, the former Gers boss believes that Mark Warburton's squad have enough quality to book their place in the top flight for next season.
"If nobody does come in, I still think Rangers are strong enough to win the league. But it would give them a helping hand if they could get a couple of players in," he told the Evening Times.
Although the last few days have been frustrating for the club, they have had some success in the transfer market recently. Both Harry Forrester and Maciej Gostomski have joined the club, while Matt Crooks and Josh Windass have signed pre-contract agreements (via Evening Times).
Despite their lack of business, Warburton's men currently sit five points clear at the top of the table, having won their last four league games.
And with neither of the new arrivals having had sufficient time to make an impact at Ibrox, it is surely fair to predict that the club's squad is already strong enough to clinch the title, as McCall suggests, and further signings will arguably only confirm that fact sooner.