Shackleton reminded the Championship of his immense potential with a stunning cameo performance in the 1-0 win at Derby County last Saturday.
It was the 19-year-old's first senior appearance under Marcelo Bielsa in over two months, but there were no signs of rust on the Thorp Arch starlet who demonstrated his defensive and attacking qualities at Pride Park.
His energy certainly added something to United in the first leg of their semi-final against the Rams, and former Leeds star Dorigo has suggested that he should play again tonight.
Dorigo told LUTV: "He's an absolute dream for Bielsa to have on bench. Pre-season was the first time I'd seen him. He was playing wing-back and I said, 'Jesus who is this right wing-back?' and the guy told me he was a midfielder!
"I watched him again and I'm thinking, 'Wow, this kid.' I like him. I think he's really good and he should play!"
The emergence of young players has been a key theme in Bielsa's first season in charge. Yes, a lot of experienced players have improved under his coaching, but he has undeniably helped the likes of Shackleton and Jack Clarke reach new levels.
If Leeds avoid defeat, they will renew hostilities with Aston Villa in the final at Wembley on May 27, after Dean Smith's side beat West Brom on penalties last night.
Shackleton might not start this evening, but what an option to have off the bench.
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