GB coach Finch has endured a tough time over the summer
Great Britain will travel to Poland for the EuroBasket finals having won only one game in nine starts this summer after losing 87-53 to Turkey in Ankara.
The result drops Britain to last place, winless in the Efes Pilsen tournament.
Jarret Hart top-scored for the first time for GB with 14 points and Robert Archibald added 10.
In a tentative display, GB trailed 22-4 early on and later were 41 points adrift in the fourth quarter before a late six-point scoring burst from Hart.
GB started without Andy Betts, who was rested with a back injury, and Kieron Achara, who still has a groin problem. Joel Freeland again sat out the game as he recovers from a gastric complaint.
"This match was always going to be difficult with so many key players missing," said GB coach Chris Finch. "I did like the way our guys played it much harder today, but we missed a lot of plays early on."
We don't want to lose games but you learn a lot more from the games you lose
GB captain Andrew Sullivan
Although the game was played on a public festival in Ankara, Finch's team discovered Turkey were in no mood to join in the holiday spirit as they fought to save face in a tournament that has gone severely wrong for the hosts.
GB were 10 points down in four minutes before Archibald got their first basket and lost the first quarter 25-12.
"Turkey came out very aggressive - we expected a big game from them," said Finch.
His team managed only two field goals in the second quarter and were 23 points behind at half-time.
Turkey, who were led by 18 points from Ersan Ilyasova, the star of the recent O2 Tournament in London, had their first 30-point lead midway through the third quarter.
Despite threes from Jermaine Forbes and Archibald to open the fourth quarter, a 40-point gap opened midway through the fourth.
"We're very disappointed that we didn't put together the big game that we were looking for," added captain Andrew Sullivan, who fouled out with five points midway through the fourth quarter.
"As a team we have to learn from this and make the necessary adjustments. We don't want to lose games but you learn a lot more from the games you lose."
GB's 53 points is their lowest score in 41 internationals since the programme restarted in 2006 and only Hart's late scoring run saved them from their biggest margin of defeat (35 points) in that period.
Their first finals game in Poland comes on 7 September, against Slovenia in Warsaw.