I heard this yesterday during a conference call.
Problem:
The phrase “up front” introduces a redundancy.
Explanation:
The speaker on the conference call was telling the other call attendees that he wanted to say something before he said something else.
The noun “preface” means a preliminary statement in a book or speech.
So the verb “preface” means to provide a preliminary statement.
And therefore following the verb “preface” with the phrase “up front” introduces a redundancy.
Solution:
“I want to preface this by saying …”