The Celtic boss has warned the 22-year-old that the club have other options.
Deila has taken an admirably strong stance, encouraging the Swede to sign a permanent deal with the Bhoys but affirming that negotiations should not all be one way.
The 22-year-old striker, on loan from Manchester City for the season, has deliberated when it comes to contract negotiations but the Celtic boss is still confident a deal can be struck.
He has, however, stressed that there are other players that want to play for the Hoops and that the Manchester City loanee, whose contract with the Premier League champions expires at the end of the current campaign, should be pleased the SPL champions want him.
“Celtic also has options, it’s not all one-way,” Deila told reporters. “We have to work to get Guidetti but he also has to be happy that we want him. It works two ways always.
"Playing at Celtic is a big thing and you can see that with other players who want to play for us. We have to look at different options if it doesn’t happen but, hopefully, it happens and I’m positive we can do it."
Celtic yesterday confirmed the signing of Dundee United winger Gary Mackay-Steven on a pre-contract agreement, meaning he will join up with the Bhoys in the summer as things stand.
Deila's men travel to Hamilton Academical later today hoping to resume their league season with a win off the back of the winter break, when they enjoyed a warm-weather training camp in Gran Canaria.