The Blues boss was taken aback after being asked about Malang Sarr and Jamie Cumming in his post-match press conference following the 3-0 win over Luton.
It was his first competitive victory since taking over at Stamford Bridge in the summer.
And following a transfer window which has seen the west Londoners splash out around £350m on nine new players, it is hard to keep count on who the club can rely on.
Football fans have joked that Pochettino is struggling with the same issue after he was asked about two of his squad players.
A reporter commented on the whereabouts of defender Sarr, who spent last season on loan at Monaco.
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To which Pochettino simply stated: "Who?"
The journalist responded by naming the player again, before asking about goalkeeper Cumming, who started his first pre-season match against Wrexham.
His questions took Pochettino by surprise, who insisted he was expecting to be asked about the game against Luton.
He remarked: "Oh my. Malang Sarr and then Jamie, yeah.
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"I don't know what I can tell you. I don't know because you surprise me. It's like you've punched me and I am like this."
Imitating being punched in the face and being dazed, Pochettino added: "We were talking about Luton! After I will explain, I wasn't prepared for this."
Fans were loving the incident, as one Twitter user said: "When your club is sooooo big, you can't remember who the hell works there any more."
Another commented: "Not a great look really. Either for Poch, or the club."
A third added: "Omg this is so disrespectful to those players!!!"
This supporter then messaged: "More evidence this club is a mess every single day."
Meanwhile one posted : "Signed so many players that the manager can't even keep up, what a club."
One then stated: "Doesn't even know his squad ffs."