Vedran Corluka believes Tottenham could finish sixth in the Barclays Premier League because of Harry Redknapp's refusal to rotate his squad.
Redknapp made fewer changes to his team over the festive period than any manager in the top flight and it paid dividends at the time as Spurs kept pace with both Manchester clubs at the top of the table.
But the Tottenham boss's failure to field some of the club's squad players led to four of them - including Corluka - leaving White Hart Lane in January, and the players that remained have tired recently.
After being 12 points clear of fourth-placed Arsenal in February, Tottenham now find themselves in fifth, three points behind Newcastle with four games left and Corluka, who is on loan at Bayer Leverkusen, fears for his parent club.
"I wouldn't be surprised if they finished sixth," Corluka told the BBC.
"They didn't rotate enough. They don't have depth on the bench.
"That's the main problem. I watched almost every Spurs game and they played them all with the same 11, 12, 13 players and that's why the players now are really tired."
Redknapp talked up his team's chances of winning their first league title since 1961 at the start of the year, but he has now had to scale back such grand ambitions.
The 65-year-old, who is favourite to become the next England manager this summer, insists finishing in the top four would be a remarkable achievement given the money spent by their rivals, but Corluka claims the north London club should have qualified for next year's Champions League a long time ago.
"Tottenham, for me, had one of the best teams in England and of course it will be an unsuccessful season if they don't go to the Champions League," the defender said.
"I don't know what the chairman will do if they don't qualify. I know only that it will be an unsuccessful season.
"Three months before they were in the title race challenging [Manchester] City and [Manchester] United.
"Now they are three points behind fourth spot. They are fifth and it's going to be really difficult for them."
In fairness to Redknapp, he has did not expect for his squad to be hit by so many injuries in the closing stages of the season.
Michael Dawson and Niko Kranjcar will miss the rest of the campaign with their respective ankle and knee injuries, while hamstring problems have prevented Aaron Lennon from getting a decent run in the side and Ledley King's chronic knee troubles have caught up with him of late.
Benoit Assou-Ekotto looks set to miss the club's remaining games with a shoulder injury and Redknapp fears Younes Kaboul may not turn out for Spurs again this term thanks to a knee problem he suffered against Norwich.
Redknapp has been boosted by the news that Emmanuel Adebayor could be fit for Sunday's home game against Blackburn, however.
The Togo striker missed Saturday's defeat to QPR with a hamstring injury, leaving Redknapp with only one fit striker - Jermain Defoe - as Louis Saha had a groin strain, but he could be back for Sunday's must-win fixture.
He said on Twitter today: "Training tomorrow, hoping to be fit for Sunday. Big 4 games coming up."