"To see Luis day in, day out has been a real eye-opener for me," he told LFC magazine.
"I knew he was a good player. Having worked with him on a regular basis I think he has the potential to be one of the best in the world." "I think the squad is looking stronger, probably the strongest we've had for a long time. Now it's all about delivering," he added.
"The tools are all there, now we need to work hard, focus on each game and try to build on what we've shown over the last 20 or so games."