The 50-year-old praised the Belgian for his adaptability in midfield, while hailing Phil Neville's influence ahead of the defender's retirement at the end of the season
The Belgium international has been one of Toffees' top performers this season, netting 11 goals and contributing five assists but also chipping in with a number of solid displays in a more defensive midfield role.
His form has seen links with clubs such as Manchester United and Chelsea intensify, but the Merseyside outfit's boss outlined the 25-year-old's influence in both roles and indicated they will fight to keep hold of him.
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"He is a good player in either role and is capable of doing both. For long parts of this season we have played him a bit further forward but recently he has dropped back a little.
"I think as he matures he might grow into a deeper role but currently he does give us a different attacking option and has scored quite a few goals so we have been happy with him playing further forward this season."
One player the club will have to do without next season is Phil Neville, with the defender announcing his intention to retire at the end of the current campaign.
Moyes indicated he will be missed during matches and around the training ground, but is confident the 36-year-old will remain in the game in some capacity.
"He has been really influential," the Scot continued. "He has been a great captain and a great player since he joined us eight years ago and will be missed. He has been someone that I can rely on both on and off the pitch.
"I have got no doubt that he will go on to work in football and he is someone who we will miss. It will be a hard position to fill because the way he has captained the team has been excellent over the years.
"Phil will be a success in whatever he does in life because he conducts himself well and is very articulate but if I was a betting man I would say that it would be coaching."
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