The Spanish coach is considered to be one of the best young managers around, but his former player Scharner has revealed to Transfermrkt the key area he still needs to improve.
His first season with Everton saw them wowing audiences, as the Merseyside club stormed up the Premier League table playing a brand of attractive attacking football associated with Martinez.
However, this campaign has not progressed in a similar manner. Attempting to play the same type of football, the Toffees have dropped points at all corners. Despite progressing well in the Europa League, Everton sit just six points clear of the relegation places in their domestic league, and Martinez has been criticised for not changing his approach to help the team.
Rather than accepting that there are deficiencies in his current system, Martinez has continued to try and fight through the problems - without much success. Considering he frequently made changes during his time with Swansea and Wigan to help the team, it comes as a surprise that he would be so against such changes currently.
One of the stars of his Wigan team was former Austria international Paul Scharner, and the no-nonsense defender has told Transfermrkt that Martinez needs to become more open and willing to accept new things if he intends to improve as a coach.
The 35-year-old said: “Martinez has great qualities in tactical and analytical terms. We were always prepared for every opponent. But it could be helpful if he accepts outside impulses in order to receive more information. You cannot know everything as a single person. You must pass on some of the responsibilities.
“He needs to become more open. You can always learn and improve.”