Ferrari's decision to extend Alonso's contract for such a long period has been interpreted as the team effectively acknowledging that would remain the case throughout that period.
That would mean drivers such as Hamilton or Sebastian Vettel, the reigning champion, could almost certainly not be accommodated.
But Domenicali, who was speaking in an exclusive interview with BBC Sport, shrugged off that suggestion, saying: "I don't think so."
It was pointed out that Alonso probably would not be very happy about having Hamilton alongside him again.
Alonso confident he can catch Vettel
Domenicali said: "Never say never - but I don't want to upset my friend Martin [Whitmarsh, the McLaren team principal] and have him think I want to have his driver. I am very happy with Felipe at the moment.
"The signal of such a long relationship with Fernando is that as strong a driver as he is giving the commitment to the team means a lot for all the people in it. It means he trusts the people here. It is an important signal and I see already the reaction from the people.
"That is what I was expecting, to see people motivated, to realise we need to look at the present but also the future. It is a key point for a strong team to have a reference guy that is in the team."
Hamilton said on Thursday: "I don't have a drama being alongside him, but I assume he wouldn't allow it to be the other way around. I don't really care. I'll beat him in another car."
Highlights - Spanish GP second practice
And Vettel, who has said recently that he would like to drive for Ferrari at some point in his career, said: "I never said anywhere that the fact that Fernando or Felipe drives for Ferrari, or any other driver, it is impossible to go there.
"As far as I know, F1 teams have two cars. Probably that kicks off some headlines! But I am very happy where I am so at this stage I don't care.
"It's nice if that's he wanted. In the end, we are all in the same boat.
"Ultimately we are looking for a package that makes us happy, whether that is results or the environment inside the team.
"At this stage, I don't really care as it is so far away. I renewed my contract [with Red Bull] at the beginning of the year [until the end of 2014)]. It is quite far away and many things can happen."
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