The Gunners have fallen away in the title race this season.
The Gunners are currently third in the table and 11 points behind leaders Leicester City after falling away in the title race this season.
Their failure to invest is more than Petr Cech last summer has cropped up as one potential cause, with many feeling they still need improving in several areas.
"We know that it will not be easy and that we need reinforcements if we want next season to be on top here again," he told welt.de.
"It is again interesting to see who invests in who and how much the clubs do during the summer break.”
"In addition, great coaches are coming into the league. I am thinking primarily of Pep Guardiola. Wherever he has been, he had success. He is a coach, keen on playing and his teams are feared.”
Whether Arsene Wenger decides to spend in the summer remains to be seen, but the consensus seems to be that three positions in particular need improving.
The first of those is the striker’s role despite Olivier Giroud impressing this season, while many still believe the side needs a world-class defensive midfielder despite Francis Coquelin’s development.
Central defence is also still an area of concern, with Mertesacker and Gabriel both having failed to impress alongside Laurent Koscielny this season, who has also missed time with injuries.