Prolific striker Gary Hooper, forward Georgios Samaras and midfielder Victor Wanyama are among the players who have been linked with moves away from Celtic in next month's transfer window, following strong showings as Neil Lennon's side advanced to the knockout stages of Europe's elite competition.
Speaking ahead of Thursday's draw in Nyon, Mjallby conceded that had Celtic not reached February's last 16 some players might have sought new challenges.
"This should be a great incentive for them to stay here at Celtic and take us forward," Mjallby said. "You never know where it's going to take us.
"If we hadn't gone through and done as well as we have I think maybe some of the players who have done exceptionally well for us would maybe be interested to have another challenge."
Hooper, in particular, has impressed, with Juventus the latest linked with the former Grays Athletic and Scunthorpe striker who has netted 13 times this season.
Mjallby appreciates why Hooper is attracting admirers, but hopes Celtic can fend off the suitors throughout January.
"I think Gary's got 18 months left on his contract and we're delighted and we want to keep him," Mjallby said. "I think there are discussions now with Gary, his agent and the club. Fingers crossed from my point of view something's going to happen.
"He's shown that he can do it at the highest level, so I can understand where the interest is coming from. It's down to Gary and what his targets are and what he's looking for.
"He's just enjoying playing football just now. He's in a good place. That's something that's always going to be important for you as a footballer. The grass is not always greener on the other side."