Newcastle are also in the running for his signature, meaning the 22-year-old Slovenian now has a big decision to make as to which project appeals most.
Should he choose the Red Devils, Ruben Amorim would be faced with a problem. How does he fit Sesko into his side alongside fellow new signings Matheus Cunha and Bryan Mbeumo side?
Standard Sport has taken a look at how Sesko could fit in at Old Trafford should he opt for a move to the north-west rather than the north-east.
Three-pronged frontline with Cunha and Mbeumo
The likeliest first-choice Manchester United line-up would feature a brand-new attacking trio.
It is widely believed that Cunha and Mbeumo have been signed to occupy the left and right-sided No10 slots in Amorim’s signature 3-4-2-1 set-up, with the towering frame of 6ft5in striker Sesko replacing Rasmus Hojlund up front.
The three scored 48 league goals between them last season, which is more than the entire United team (44) managed in the Premier League.
Amorim opting for this line-up would mean Bruno Fernandes dropping back into a deeper midfield role instead of occupying a No10 spot himself.
That is something we have seen before from the Red Devils captain, and have continued to see in pre-season. Fernandes is a capable ball-winner as well as a creative force, and could continue to serve as the side’s metronome regardless of his starting position.
Manchester United XI (3-4-2-1): Onana; Yoro, De Ligt, Martinez; Amad, Fernandes, Ugarte, Dorgu; Mbeumo, Cunha; Sesko
It is possible, however, that Amorim prefers to keep Fernandes at No10.
This may happen against stronger opposition, to allow for a pair of more defensive-minded players – for example, two of Ugarte, Mainoo and Casemiro – in the middle of the park while still keeping the captain’s creativity in the side.
There’s a chance that having a creative-minded player like Fernandes directly behind him could also help provide more chances for Sesko than if both Mbeumo and Cunha took up the No10 roles.
One key issue with this potential line-up is that it would probably mean benching one of the club’s major new signings. That could be Cunha or Mbeumo, with the former more of a crafty playmaker and the latter a more direct goal-getter.
Both could serve as super-subs for Amorim, though, capable of bombing forward to link up with line-leader Sesko.
Manchester United XI (3-4-2-1): Onana; Yoro, De Ligt, Martinez; Amad, Ugarte, Casemiro, Dorgu; Fernandes, Mbeumo; Sesko
This is perhaps the least likely option, given Amorim has shown few – if any – signs of veering from his preferred 3-4-2-1 formation.
With the personnel available to him, though, there’s always a chance the Portuguese chooses to experiment. Should that be the case, there’s still a way that all three of Sesko, Cunha and Mbeumo could fit into a United XI alongside Fernandes.
The captain could pair up with Ugarte in midfield, with Cunha operating as a sole No10 in a tweaked 3-4-1-2. That would mean Mbeumo being shunted out to right wing-back.
It’s a scenario which may seem unlikely, but the Cameroon international played a similar role on a few occasions for former club Brentford, and has a commendable work rate for an attacker, so shouldn’t have an issue adjusting to the defensive duties required. Amorim also likes his wing-backs to be capable going forward, which we know would be no issue with Mbeumo.
That would leave an open spot in the front two alongside Sesko, which could be filled by Joshua Zirkzee or Rasmus Hojlund, provided they stay at Old Trafford this summer.
The versatile Mbeumo could also slot into the frontline beside Sesko, allowing Amad, Diogo Dalot, or Noussair Mazraoui to slot in at right wing-back.
So too could Cunha, who has featured up front in pre-season as well as for previous employers Wolves, but the Brazilian has more experience as an attacking midfielder.
A two-striker setup could suit Sesko, who has spent time at Leipzig playing alongside another forward in Lois Openda.
Manchester United XI (3-4-1-2): Onana; Yoro, De Ligt, Martinez; Mbeumo, Ugarte, Fernandes, Dorgu; Cunha; Zirkzee, Sesko