Sesko fired an unstoppable finish past Liverpool goalkeeper Adrian midway through the first half and also caught the eye with a sensational piece of skill that left James Milner sprawled on the floor.
United are reportedly interested in signing the Slovenian striker, who has scored 12 goals in 38 games for Salzburg.
After transfer expert Fabrizio Romano reported United were keen on the forward earlier this month, Salzburg’s Twitter account posted: “We want 300million + Bruno [Fernandes]”, along with a thumbs up emoji.
But after Sesko scored against Liverpool, the Austrian club upped their demands for the striker.
“Update: We now want 1 billion, Bruno and Fred the Red for Sesko,” the Austrian club tweeted.
Despite those claims, Salzburg are believed to have slapped a more realistic price tag of £55m on Sesko, according to The Sun.
They are said to be eager to keep him for at least one more season if that valuation is not met this summer.
Speaking after the defeat to Salzburg, Liverpool boss Jurgen Klopp admitted his side underperformed in their final warm-up match for Saturday’s Community Shield match against Manchester City.
“First half we made too many mistakes, which they could use,” Liverpool manager Klopp said.
“We had good moments as well, we could have scored four or five goals at least. Didn’t do that because we were in the first half we were too open, we were too wide, we were not connected enough in moments when you lose the ball.
“Then everything is open, it’s like a motorway, and with their speed that’s how they had their chances, especially when you lose simple passes where nobody can react. T
“hey scored their goal and the last half an hour was like a thunderstorm, we were really like a truck, but we didn’t finish the situations off. Obviously we should involve that in our game as well and then it will be fine.”