Jackson Martinez
Jackson Martinez has been linked with Arsenal and Manchester United. Getty

Arsenal and Manchester United have suffered a massive blow in their ongoing pursuit of signing star Jackson Martinez.

According to the Italian publication Tutto Mercato Web, Valencia have reportedly joined the race for the FC Porto striker's services.

The 28-year-old has been in fine form for the Portuguese club and is the league's top scorer with 21 goals. His impressive display has helped him make it to Colombia's squad for the upcoming Copa America in Chile.

Martinez has been attracting interest from top clubs in England as the Gunners and the 20-time English champions were keen on securing his services. However, Arsenal manager to beat United and rumours suggested the north London club had agreed a deal in principle.

However, both Arsene Wenger's side and United have lost the race as Valencia have now taken the lead to land Martinez. The La Liga outfit were keen on securing his signature last summer.

After failing to sign the South American goal-scoring machine, Valencia will be looking to seal the deal for him in this summer transfer window. Martinez is represented by Jorge Mendes and the Spanish side believe their relationship with the player's representative will help them land the frontman.

Porto have already confirmed the signing of Alberto Bueno as speculation continues to grow regarding Martinez's future. The arrival of Bueno as a free agent from Rayo Vallecano suggests the Portuguese club are already preparing for life without the Colombian star.

Arsenal retained the FA Cup after sealing a 4-0 victory over Aston Villa in the final at Wembley on 30 May. Wenger started Theo Walcott ahead of Olivier Giroud and the Gunners manager believes the England international can play in the middle for the Emirates club.

"He [Walcott] can play on the flank, but if you ask me where do I see him in the future, it is through the middle. If you ask him, he will tell you as well through the middle," Wenger said.

"Why? Because he is a good enough finisher, he has electric pace and he has top, top quality in the timing of his runs. If you analyse that, it is the quality of his receptions, the space where he gets the ball basically, that is above average compared to many players."