Talks continue between Arsenal and Sporting over the signing of striker Viktor Gyokeres as a gap in the valuation of the striker remains between the two clubs.
Sporting are thought to want £69m including add-ons for the 27-year-old.
While the clubs aren't too far away from a compromise on an overall fee, it's thought how much of that fee will be guaranteed is key.
Arsenal are understood to be encouraged and impressed with the player's desire to join, but they will be disciplined in their approach.
They have done due diligence on other targets if a deal cannot be struck with Sporting.
Sporting have given Gyokeres permission to delay his return for pre-season.
The Sweden international was due back on Monday - a week after some of his team-mates - but he has now been given until Friday as talks with Arsenal progress.
After joining Sporting from Coventry for around £20m in 2023, Gyokeres has scored 97 goals in 102 matches during his two seasons in Portugal.
Gyokeres hit 54 goals in 52 games in all competitions during the last campaign, including a hat-trick against Manchester City in the Champions League, as he helped Sporting win the league and the Portuguese Cup.
A move to Arsenal would see Gyokeres return to English football, having joined Brighton in January 2018 before moving to Coventry after loan spells at St Pauli and Swansea.
Gyokeres scored 43 goals for Coventry in his two and a half seasons at the Championship side.
Eze still primary target for Arsenal
Meanwhile, Crystal Palace forward Eberechi Eze remains a primary target for Arsenal in this window.
Internal discussions are continuing over the next steps.
Arsenal know they can speak to Eze if they meet his release clause at Palace, which is believed to be an initial £60m plus £8m in add-ons.
However, if they want to negotiate on the clause, they will be required to approach Palace.
Arsenal are understood to be encouraged by Eze being open to a move to the Emirates.
Gunners to approach Chelsea for Madueke after CWC
Sky Sports News also understands Arsenal will formally approach Chelsea over the signing of forward Noni Madueke once the FIFA Club World Cup is over.
Madueke has emerged as a top target for Arsenal - they have followed his development over the past couple of years.
Madueke started on the bench in Chelsea's last two games at the Club World Cup.
It's believed Madueke is open to the move.
Real Madrid's Rodrygo, Aston Villa's Morgan Rogers and Newcastle United's Anthony Gordon are other players Arsenal have looked at.
A deal for Rodrygo appears difficult given the finances involved. He has made just one start for Real Madrid in the Club World Cup.
Arsenal expected to return with improved bid for Mosquera
Meanwhile, Arsenal are staying patient and remain relaxed in their pursuit of Valencia defender Cristhian Mosquera.
Valencia are thought to want €25m for Mosquera.
However, the feeling is Mosquera wants to join Arsenal. He has entered the final year of his contract and has not signed a new deal.
There is an expectation Arsenal will go back in with an improved offer after their initial bid worth €15m was turned down.