Celtic 'chose Dedryck Boyata ahead of Danny Wilson'
Wilson signed for Rangers this week after leaving Hearts.
"We had a lot of options at Celtic and we went for Boyata from Manchester City and we are very happy with that," said Deila when asked about Wilson.
Deila said he is confident that his present squad is good enough to qualify for the Champions League group stage.
The Norwegian failed to guide his side through the qualifiers last season but stressed that Celtic are much better prepared this time than when he succeeded Neil Lennon shortly before last summer's campaign.
"It has to be someone who can make a difference in the team," he said when asked about the possibility of new signings. "I am very happy with the squad and it is about consistency and keeping what we have here."
Deila insisted that Virgil van Dijk would remain with Celtic - for the time being - despite the Dutch central defender being quoted in newspapers about his desire to move to a bigger league.
"He is a very important player for us and his biggest task is to get us into the Champions League," he said, adding that he was "not aware" of any interest from other clubs.
"I have been very clear to him and everyone else that he is going to stay here for those qualifiers."
Some suggested that speculation about his future hampered Van Dijk's performances last summer, but Deila said that would not happen again.
"He is one year older and one year more experienced," he said.
Deila also insisted that Scotland winger James Forrest would be staying with Celtic despite being linked with Lennon's new club, Bolton Wanderers.
"Why go to Bolton?" said the Celtic boss. "James Forrest is a very important player for us and we want to keep him here.
"He has been injury free for six months now and we expect more from him next season."
Deila believes that Belgium international Boyata will prove to be a good replacement for Jason Denayer, who returned to Manchester City at the end of his loan spell.
"We have a lot of central defenders and, if we can keep what we have, we don't see any reasons to get one in," he said.
"Charlie Mulgrew and Mikael Lustig back in full training now and that's like two new signings.
"We have Dedryck in now and he is a great talent.
"He has high ability, but he needs matches and our task is to get his potential out.
"If we can do that, we have a top international player."