The 21-year-old was thriving in Scotland, and amassed 20 appearances in the first half of the campaign before Liverpool opted to recall him from his loan.
However, as reported by the Athletic late on Friday, Beck will actually not be eligible to play at the Emirates due to a one-match suspension that he brought with him from Scotland.
The young defender collected two yellow cards in the Scottish League Cup all the way back in July, triggering a suspension he was yet to serve as Dundee did not progress further in that competition.
And now, as a cup match beckons for Liverpool, Beck must serve his ban despite the two teams operating in two different countries.
Liverpool seem to have been unaware of this when they chose to recall the left-back, with the club posting an official injury and suspension update earlier on Friday which had no mention of Beck.
Jurgen Klopp, too seemed completely unaware in his press conference on Friday morning and was full of praise for Beck, who now misses out on what was a realistic opportunity to make his full debut for the club against Arsenal.
“At Dundee everything was fine, and he made big steps,” praised Klopp. “Now the situation here is clear – we lost two of our left-backs so it makes a sense to bring back a boy we like who is available to us.”
The caveat we now know is that he is not available on Sunday, however, with Tsimikas and Robertson unlikely to return this month, he could still prove valuable for the manager.