Show that you are ready to listen
The fear of hurting feelings, or of saying things that could
come back to haunt him later, may lead a co-worker into a certain
deferential posture.
The only way to free his tongue: show a real openness to what will be expressed, positive as well as negative.
Emphasize, for example, that his feedback is important to you,
for continuing to work on your management and for being more effective.
Abolish immediate justification
A natural temptation when we are called into question: to defend
ourselves right away with justifications, by offering "good reasons
for..."
You can of course offer your thoughts on what has been
expressed, but only after having pursued questions to understand the
message thoroughly.
A co-worker who shares his perceptions also expects a response.
How do you receive his feedback? What will you do with it? There's no
obligation to respond in the heat of the moment, because
you may also need time for assimilation and reflection.
But afterwards it could be useful, for example, to take a key
point from what was said and make it an area to work on improving.
The icing on the cake: to involve your co-worker in evaluating your progress!