The Norwegian changed all but one of his starting line-up from the side which earned a creditable 1-1 draw in their first leg play-off tie against Maribor in midweek, only to watch his side succumb to their first league defeat of the campaign and fail to score for the first time in a league match since December 2012. They currently trail early leaders Inverness by four points.
Deila said that only the result on Tuesday night will determine whether it was a gamble too far.
"I learned a lot, in every match you get new answers," the Norwegian said. "But maybe it was too many new players at the same time and we didn't get the performance we wanted and needed. We will see on Tuesday whether we regret it or not.
"I didn't want to lose today," he added. "That was not in my plans. But Inverness were good and I can understand why they have 10 points. Congratulations to them - that is also important to say."
While it is now too late to add players before Tuesday night's Champions League second leg tie, Deila said the club were closing in on a number of new players before the transfer window closes a week tomorrow.
The loan deal from Russian side Rubin Kazan for Ghanaian winger Wakaso Mubarak is subject to work permit negotiations, and the club remain in pursuit of Serbian targetman Stefan Scepovic from Sporting Gijon and others, but any business is unlikely to be concluded until the outcome of the tie with Maribor is known.
"We are getting closer, we are going into the last week, so I think things will happen now," said Deila. "They can't affect the game on Tuesday anyway - so it is more to get ready now for September 1."