James reunited with Ancelotti at Goodison Park last summer, arriving on Merseyside from Spanish giants Real Madrid on a free transfer.
The Colombian had a strong start to life at Everton but fitness issues have forced him on to the sidelines for multiple spells.
James, who missed the whole of March through injury only returned back to training last week, but Ancelotti is still delighted with the impact he has made in Everton colours and stressed he increases the technical capacity of the team.
Ancelotti explained it is no coincidence Everton score more gaols with James pulling the strings in the final third which has also played part in raising the fighting spirit of the team.
“Compared with last year, this [Everton’s fighting spirit] has improved immeasurably”, Ancelotti told The Athletic.
“In very complicated games and different situations, we have done really well.
“It is clear the quality of the team is more defensive than offensive and it is true that with James Rodriguez, the technical capacity of the team grows a lot.
“In this last period, we have not had him and it is not a coincidence that we scored a lot more goals with him fit at the start of the season.”
Everton are set to host Crystal Palace in the Premier League on Monday and it remains to be seen what role if any James will play in the clash.