The Gunners look likely to finish in the top three this season after a 1-1 draw with fourth-placed Manchester United at Old Trafford on Sunday afternoon.
The north London side have been linked with a move for out-of-favour Chelsea goalkeeper Petr Cech in recent weeks as well as Real Madrid captain Iker Casillas.
Former Arsenal striker Henry believes it is vital his old manager Wenger looks to match the spending of their closest rivals in the summer transfer window.
“You know Chelsea are going to [strengthen], you know Manchester City are going to do it,” Henry told Sky Sports News. We’ve been through that a lot. Arsenal need to do it.”
Borussia Dortmund midfielder Ilkay Gundogan is another name being linked with a possible switch to the FA Cup finalists after the Germany international confirmed his intention to leave BVB in the summer.
On Saturday, former Gunners midfielder Paul Merson suggested that Arsenal could make an audacious swoop for former Tottenham Hotspur winger Gareth Bale.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news