The Spurs left-back faces a late fitness test after suffering a gash on his knee against Leicester this past weekend.
In any case, Pochettino is certain that the Tottenham star won't be starting the first leg of tomorrow's last-16 clash at Wembley.
So who will?
The Lilywhites boss could either use Jan Vertonghen or Kyle Walker-Peters as left-back options, or even potentially Serge Aurier.
Vertonghen has plenty of experience in that role, given that he has played there many times for Belgium, and fans of the North London club believe he is a much better option than Walker-Peters, considering who he'll be marking.
All eyes will be on 18-year-old Dortmund sensation Jadon Sancho, with the London-born winger proving himself a revelation for the Bundesliga leaders this season.
I'd rather Vertonghen tbh, Sancho would rip KWP a new one— My one and only club #COYS #TTID (@del_boy_alli) February 12, 2019
If this is true, it’s gotta be Vertonghen at LB. We saw that KWP isn’t ready to start a game of this magnitude. https://t.co/4lot1oGrsG— Moussa Sissoko, a calming influence (@AGreenberg22) February 12, 2019
Please put Vert there... KWP be useless at LB— raks⚜️ (@mpho_alone) February 12, 2019
Would be a big blow but JV is still quality at left back.— 75 Retro (@75Retro) February 12, 2019
I really rate jan at left back, no problem with that...shame rose might be out tho, I thought we’d seen his best days but recently he’s been immense!!— ben allen (@benallen202) February 12, 2019
Sancho, who has eight goals and 11 assists in all competitions this season, is bullet-fast and therefore Walker-Peters might actually be a better option in that regard.
But this won't be Vertonghen's first rodeo. He has marked lightning-quick wingers for Belgium in the past and has coped well, nullifying their speed, but time will tell who Pochettino deems to be the best option.