Tonev is the subject of an SFA investigation into the allegation made by Logan following Celtic’s 2-1 league victory over Aberdeen in Glasgow on Saturday.
The Bulgarian international, on a season-long loan from Aston Villa, faces a maximum suspension of 16 games if he is found guilty of the offence.
Aberdeen have already stated their “unconditional support” for English full-back Logan as they await the outcome of SFA compliance officer Vincent Lunny’s enquiries which will determine whether Tonev has a case to answer.
Now Deila has publicly backed Tonev, declaring he has no doubts the 24-year-old did not make the comments Logan has accused him of making.
“I know he didn’t do it,” said Deila. “The club made a statement [saying they had spoken to Tonev who denied the allegation] and I trust my players.
“He is an honest player and I believe in what he is saying. We have not wasted any energy on that at all. He seems very comfortable.”
Asked if he had laid down a code of conduct to his players since becoming manager, Deila expressed his confidence that is not necessary.
“We haven’t talked about it because it hasn’t been an issue,” he said. “Everybody knows we don’t want to be associated with those words. I trust my players and he [Tonev] hasn’t said it.
“There are no problems with the other members of the squad. We are in a good mood and it is nothing we have used energy on.”
Tonev played for 71 minutes in his Celtic debut against Aberdeen and is in contention to make his first European appearance for the club tonight when they open their Europa League Group D campaign against Red Bull Salzburg in Austria.
Deila has no concerns over the player’s state of mind in the wake of the weekend controversy and is looking forward to stepping up his involvement in his team over the coming weeks and months.
“He is mentally good,” added Deila. “It was a good experience for him on Saturday. He played for more than an hour and was part of a victory.
“He needs to play games. He hasn’t played for a long, long time and that’s the problem with a lot of the players we have. They have been in and out for a while.”
Celtic will again be without defenders Mikael Lustig and Adam Matthews, sidelined with groin and calf injuries respectively. Charlie Mulgrew was also absent from the squad which travelled to Salzburg, the Scotland midfielder having sustained a knee injury while on international duty against Germany 11 days ago. Swedish striker John Guidetti is ineligible for Europa League group fixtures following the late registration of his loan move from Manchester City.
“Some of the players are closer to coming back again than others,” said Deila. “But we need to be careful and do the right things with them. Then we can get some consistency in our play, but that takes time. We have a big squad with us in Austria, 20 players are here, and we are looking forward to the game.”
Deila could hand a debut to Ghanaian winger Wakaso Mubarak tonight. Signed on a season-long loan from Russian club Rubin Kazan, he was left out of the squad on Saturday as he did not return from international duty until late on Friday night.
“He has been training this week and looks good,” said Deila. “He is a quick player, a hard-working player, so we’re looking forward to seeing him in the match.
“Could he make an impact for us in this tournament? Sure, he could do that. Again, he hasn’t played many matches in a while but we have a lot of games coming up so we need everyone in the squad.”