Manchester United have turned their attention to three potential signings after deciding not to pursue Alexander Isak . The Newcastle United striker has expressed his desire to leave the club , but the Red Devils have confirmed they won't be vying for the Swedish international's services. It would likely require a hefty sum of around £150million to convince Newcastle to let go of their star forward, a figure currently out of reach for United. Regardless, Newcastle have so far insisted they have no intention of selling the 25 year old, despite interest from Liverpool. Isak was notably absent from Newcastle's pre-season tour of Singapore and South Korea after informing the club of his wish to move on. However, United are looking elsewhere. Ruben Amorim's team are yet to secure a new striker after their bid to sign Liam Delap fell through, with the forward choosing Chelsea instead. Having already splashed out significant sums on Matheus Cunha and Bryan Mbeumo, United are considering what is financially viable. Potential deals for Aston Villa's Ollie Watkins, PSG's Randal Kolo Muani and Juventus striker Dusan Vlahovic have been explored, according to ESPN. Despite the departure of Marcus Rashford to Barcelona providing some financial leeway, sales are deemed 'essential' for any major signings, reports the Mirror . Aston Villa have already made it clear to United that Watkins is off the market after they expressed interest in the striker. Watkins is reportedly not available at any price - a stance that saw Villa swiftly reject a £60m bid from Arsenal for him in January. Kolo Muani, on the other hand, might be a more feasible target. Paris Saint-Germain are said to be open to letting the Frenchman go, following his loan spell at Juventus last season. However, the Italian club is finding it difficult to meet the financial demands of a permanent transfer. Kolo Munai has been offered to several teams, with Chelsea and Arsenal focusing their attention elsewhere, but Newcastle could pose a challenge to United's pursuit. According to reports, PSG might agree to another loan deal for the striker, provided it comes with a commitment to buy him outright later. A direct transfer would require a fee of around €50m (£43.65m). Meanwhile, Vlahovic's current club, Juventus, are also keen to move him on before his contract expires next year. However, the Serbian forward seems happy to see out his contract.