The Port Vale manager, John Askey, claimed to have been told this week that Clark had signed for Leicester after leaving Aston Villa, who loaned him to the League Two side last season.
But Nicell's appearance comes somewhat out of the blue.
As far as we know, the 19-year-old still has more than 11 months left on his contract at Leeds.
It could be that Nicell has already signed for Leicester, with youth team transfers often going unannounced, or that he is simply on trial.
Nicell helped Carlos Corberan's Under-23s to the Professional Development League 2 title last term, but unlike several of his young colleagues the Irishman has failed to appear in any of Leeds' pre-season fixtures.
Would the Leeds United and former Aston Villa players make good additions for Leicester City?
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