Manchester United don't need to convince Šeško to join them this season because Šeško has made it known to Leipzig and Newcastle United that he wishes to play for Manchester United, just the way Gyokeres made it known to Sporting CP and Manchester United that he wishes to play for Arsenal. The ball is now in Manchester United's court, and since Šeško wants to join Manchester United, the only thing that will stop Manchester United from signing Šeško from Leipzig is if Manchester United fails to meet Šeško's transfer fee.
It seems Manchester United will have to think more seriously about this if they want to bounce back next season. After such a poor season for themselves last season, at least Manchester United should be grateful that one of their players immediately wants to join the team, despite Manchester United's poor results last season. I hope Manchester United will pay the transfer fee for this player so that Manchester United's squad next season can be different and better than last season. Although I don't think Manchester United will be title contenders next season.
Manchester United seem to be a bit serious towards the end of the transfer market and they are trying to sort out their team. I don't know how much they can strengthen their team in this short time. We have seen poor performance from Manchester United in the previous seasons so at least we will have expectations of good performance from Manchester United in the next season. Although it is still difficult for Manchester United to perform well, they will still have to try and plan match by match. If they play football thinking that they have to win the match they have in front of them by any means, if they cannot win then they have to earn at least one point. If such a plan is in mind, their position will already come towards the beginning of the points table.