Last season's Champions League finalists have already made high-profile additions as they bid to remain at the top of European football in 2022-23.
However, both clubs continue to be linked with other players, and it appears that they are each considering whether to try to secure the signature of one of the continent's top prospects.
According to Fichajes, Sesko is on the radar of the Merseyside giants and Los Blancos having made an impression in Austrian football.
The 19-year-old provided 10 goals and seven assists from 37 appearances in his first full season with Salzburg, eight of his contributions coming in the Bundesliga.
Despite his age, Sesko has already earned 13 caps for Slovenia, and is drawing comparisons with former Salzburg forward Erling Braut Haaland.
With four years still remaining on his contract, Salzburg are unlikely to be in any rush to part ways with a player whose value could rise over the next 12 months.
Nevertheless, much could depend on the size of any proposal put forward, while the player himself may want to take any opportunity to move to the Premier League or La Liga.
As well as Spurs, AC Milan are monitoring the situation with Sesko's agent allegedly having held discussions with officials at the Serie A champions.
Prior to making an impact in Austria's top flight, the youngster starred in the second tier with Liefering, scoring 21 times in 29 outings.