Hill has heaped praise on the man who he brought in to help steer the Warriors back into the English elite as he now begins the hunt for a new N0.2 to take on the development of the forwards at Sixways.
"I have known Phil for a long time, since our Level 5 coaching course days. We always spoke a lot and wanted to work together. When I got the job at Worcester I wanted to bring him in, he was always my choice. I'm delighted we've had that opportunity to work together," he said.
"Phil has brought huge energy and massive enthusiasm to the role and we will all be sad to see him go. He loves being on the training park showing everyone he can still kick off his left foot and demonstrating all the skills he showed for Scarlets and Wales.
"Phil has been extremely loyal to me and I have enjoyed working with him a huge amount. He retains huge ambition in the game and the role at Cardiff Blues is a massive opportunity for him, we understand that and we wish him well.
"This move does, however, mean we will have a great relationship with Cardiff Blues and that can only be beneficial to the Warriors, with things like pre-season training and player sharing. I'm sure it can be a two-way process with a great Welsh region."
The process to find the next member of the coaching staff at Warriors is now underway and Hill stressed the importance of making the right appointment.
"When we were aware that there was a possibility Phil could go then the process started then, we are already down the line with it," he said.
"A job like the one he held at Worcester is held in high esteem and we have had, and will continue to get, huge interest in it. There is no shortage of people that would bite your hand off to get this role.
"It is a key appointment and I must get the right person to work with. We have an impressive pack of forwards who have got to feel they can move forward rather than take a step back under the new coach.
"Phil will leave some big shoes to fill, quite literally, and my job is to get the right person. I am not going to rush into it. I will take my time and speak to a number of people who I think could do the job and make a big impact at the Warriors."