Playmaker Ozil returned from hamstring trouble to help The Gunners claim a comfortable 3-0 Barclays Premier League win at Hull on Sunday.
The big-money Real Madrid summer signing has failed to sustain his early Emirates Stadium impact, but defender Mertesacker believes the 25-year-old can prove any detractors wrong next term.
"It's very important to understand how the differences are between the leagues," Mertesacker told Arsenal's official website of Germany colleague Ozil.
"I think he came from La Liga and it's quite different to play there.
"He has adapted well but there is more to come from him, and I think the second season will be much better from him, because he's a fantastic player.
"He has shown some great skills but he needs to be more consistent, and that's what makes the difference at the end."
Arsenal face Newcastle, West Brom and Norwich in their quest for a top-four Premier League finish to secure Champions League football for next season.
Arsene Wenger's men then take on Hull once more in the FA Cup final, following their penalty-shootout victory over Wigan in the competition's last four.
Mertesacker believes influential midfielder Ozil is exactly the kind of smart-thinking footballer who can use criticism of his game constructively as he bids to make a success of his time in English football.
"Sometimes it's good to get criticism, to get the negative points," he said.
"I think if you realise quick what it needs, if you are intelligent enough, and he's an intelligent footballer, and I think he will sort that problem out.
"It's similar to myself, when I got my injury in the second part of the season, and afterwards I came back even stronger: because then I realised what is at stake.
"And I think for him it's good to get a little rest now, to be ready maybe for the last few games for us, the World Cup, and then another season.
"With a pre-season ahead of him, there's more to come from him."
Source : PA
Source: PA