Farhad Moshiri’s 49.9 per cent purchase of the club's shares means that Everton could be set to spend considerable amount of money in the summer in order to reinforce the squad for the 2016-17 campaign.
"I think that the concern will be why should they invest money in the club when the manager isn't getting the best out of his current squad?” Nicholas told Sky Sports.
"Bill Kenwright has done a fantastic job as chairman and would love to keep Martinez, but the investors will be asking whether they'll be giving their money to the right man to spend. They've already got a strong squad and it's not working.”
Martinez has been in charge of Everton since 2013 and is a very good manager, but he has come under pressure this season.
The Merseyside outfit could finish outside the top 10 of the Premier League this season. The only positive in Everton’s campaign is that they have a chance of winning the FA Cup.
The Toffees have reached the semi-finals of the prestigious cup competition and will take on Premier League rivals Manchester United for a place in the final.
The current Everton squad comprises of talented young players such as John Stones, Romelu Lukaku, Ross Barkley and Gerard Deulofeu, but they have been severely underperforming all season.