The Finn formed a close bond with Slade during his spell at McLaren, and was instrumental in getting Lotus to hire him when he returned to Formula 1 at the start of last season.
Although some consideration had been given for Slade to follow Raikkonen to Ferrari, it is now looking likely that his new Maranello bosses will use someone from their current talent pool to work with Raikkonen instead.
Despite admitting that Slade's presence at Lotus had been important for getting him back up to speed in F1, he says that not having him at Ferrari will not be a problem.
"I enjoy working with him and we have been achieving good results with him," explained Raikkonen.
"But I know the people from Ferrari, and I achieved good results there.
"For me, it was important to have him here [at Lotus] when I came because he was in the team, he knew the team and I know him.
"It made my life easier and I could get into the team slightly easier, which is why I wanted him here to work with me.
"It has been a good two years but we see what happens next year."
Raikkonen was initially engineered by Chris Dyer when he joined Ferrari in 2007, before Alonso's current engineer Andrea Stella took over in 2009.
Stella has formed a strong partnership with Fernando Alonso since then, and there appears little reason to break them up.