By Rob Dugdale
BBC Sport in Tel Aviv
Deng recently re-signed with the Bulls in the NBA
Great Britain narrowly lost their opening European qualifier away to Israel 102-92 after overtime.
Luol Deng hit 30 points on his return to the team and Joel Freeland added 14.
GB were the better side in the first half but Israel hit back, with Meir Tapiro scoring 17 of his 27 points in the host's second half comeback.
Two Tapiro free throws levelled the scores with 0.5 seconds left and when Deng and Pops Mensah-Bonsu fouled out Israel proved too strong in overtime.
Great Britain led 85-83 after Nate Reinking scored a free throw with 3.4 seconds remaining, but when he fouled Tapiro the Israeli guard made no mistake from the free throw line.
With the game in the extra period the absence of Mensah-Bonsu and then Deng left Britain short of scoring options.
That shortage showed as they scored just two more points in overtime, while Israel finished with a flourish, hitting two three-pointers in the final minute.
GB now have to come back from the loss to face the Czech Republic at the O2 Arena on Saturday, the first of three successive home games for Chris Finch's men.
The Czechs won at home in their opening game, beating Bosnia-Herzegovina 70-56.
Great Britain assistant coach Tony Garbelotto admitted the defeat was hard to take.
"We're all devastated - we're upset that we've let something slip that we shouldn't have let slip," he told BBC Sport.
"But this isn't a pro-basketball club where we have seven days, two of them moaning and groaning at people, we've got to turn it all around and do it all again in three days.
"Not trying to make excuses, we lost our best players and it was a struggle from there.
"Israel took us more than seriously but we've got to close these games out. We are sending the message out that we're there or thereabouts with a European powerhouse.
"We were in the lion's den with an incredible atmosphere in Tel Aviv, against a team with several Euroleague players. We lost two players and played in foul trouble all of the way and yet we competed all the way and got ourselves into a position to win the game."
Although an away game against the group's top seeds might seem like a tough start to a qualification campaign, Garbelotto sees the Israel defeat as an opportunity missed.
He's going to get better and he won't take this lying down
Tony Garbelotto on Luol Deng
"We really targeted this game and really thought we could get this one won on the road and kick-start ourselves in a massive way," he said.
"Now we have to do what every team that wants to qualify has to do and that is close three home games out."
The main positive he takes from the game is in the performance of 6ft 11in Gran Canaria forward Joel Freeland, who added nine rebounds to his 14 points in his most assured international performance so far.
Garbelotto added: "I told Joel after the game, 'you can take the game DVD, take the stats sheet and put it in the post to Gran Canaria because that was an outstanding performance'.
"I thought he was fabulous in every facet of the game. He kept his turnovers down and made the big plays down the end to keep us in the game."
Garbelotto vowed that there was more to come from Deng, adding: "He wasn't in tip-top shape, he hadn't been integrated into our systems fully.
"But my goodness, if you can score 30 points in a game like that if you haven't practised for two or three weeks, that just shows you his character and his competitiveness.
"He's going to get better and he won't take this lying down and between him and the rest of the team I think they're going to rebound really well."
All eyes will be on the O2 Arena on Saturday, the first time the 2012 Olympic venue has been used for a competitive international fixture.
"We've got to come up with a win first and foremost on Saturday," said the assistant coach.