Professor deviating from the syllabus mentioned apriori
Yes, you can speak with both of them, but in the spirit of enquiry, not condemnation. There may be good reasons for it and you have a right to know such things. You especially need to know how much the testing/evaluation framework will follow the original syllabus. And a bit more lead time than &quot;the day of the lecture&quot; is useful for the best students who might be inclined to study ahead of lecture.
Some adjustments may be necessary in the course and your enquiry might lead to them, but it might also lead to a deeper understanding on your part of what is more important in this subject.
There might be a lot of reasons for a deviation, including an inexperienced instructor - or a very experienced one.
And you are in a better position to make guesses about personalities and the effect of an enquiry than anyone here. A reasonable person shouldn't take questions about the syllabus and the expected learning as confrontation.
And, of course, there is also the question of how much scaffolding the professors provide for your learning.