<text>  Arsenal manager Arsene Wenger will target a central defender, a holding midfielder and a goalkeeper this summer with a 50million transfer war chest. Per Mertesacker could pay for some poor performances this season, with Dortmund centre half Neven Subotic and Aleksandar Dragovic of Dynamo Kiev on the Gunners radar. Arsenal goalkeepers David Ospina and Wojciech Szczesny will also be sweating on their futures. Petr Cech is a possible target, although Chelsea may not be prepared to sell to a rival. Arsene Wenger is said to be eyeing a swoop for Borussia Dortmund defender Neven Subotic left Aleksandar Dragovic second right of Dynamo Kiev is also on Wengers radar for a summer swoop . Arsenal manager Wenger reportedly has a budget of 50million to spend on his squad in the summer . Wenger is a long-term admirer of Southamptons Morgan Schneiderlin, who is the leading contender for the midfield holding role. Gabriel and Laurent Koscielnys place in Arsene Wengers plans for next season look secure. But the arrival of a new centre back in the summer is likely to have repercussions for Mertesacker. The Germans performances have been criticised this season, though he was excellent in Mondays euphoric FA Cup win over Manchester United. Wenger has been repeatedly linked with Southampton midfielder Morgan Schneiderlin left Chelsea keeper Petr Cech is also said to be of interest to Arsenal but Chelsea may not want to sell to a rival . He was recently dropped by Wenger, but Gabriels hamstring injury has seen the defender handed an instant route back into the first-team. And the arrival of a new centre-half could marginalise Mertesackers role in Wengers plans. The capture of a new central defender could also have consequences for Calum Chambers. The England international has been used as cover at centre-back this season, but the clubs transfer plans could mean Wenger sees his long-term future at right-back or holding midfield. 