One of Pochettino's first acts as Tottenham Hotspur head coach was selling Sigurdsson to Swansea City.
One of the Argentine's first acts as Tottenham head coach was to sanction Sigurdsson's departure to Swansea City in exchange for left-back Ben Davies in 2014.
However, the playmaker has excelled at his former club, scoring 25 goals in 86 games since his return, and, according to Pochettino, is now the perfect player for Spurs.
"After he [Sigurdsson] moved to Swansea, we saw him develop," the 44-year-old said, as quoted by the Daily Mirror.
"I think he is a perfect player for us. But, in that moment, it was the club's decision, his decision to move to Swansea and find another way.
"Every time we've met him, he's shown his qualities, not just as a player, but as a man.
"All the people here talk about him very highly. It's a shame, but that's football. Sometimes you spread your weight. But you never know in football."
Sigurdsson returns to White Hart Lane in the Premier League this weekend, with Swansea looking to build on last weekend's dramatic win 5-4 over Crystal Palace and climb out of the bottom three.
Were the Swans to lose their top flight status next season, it is likely that Sigurdsson would leave the Liberty Stadium, and there would perhaps be no shortage of suitors, with Everton said to have been keen on the Iceland international during the summer transfer window.
Given Pochettino's comments, however, the Toffees may have Tottenham Hotspur to contend with.
Would you take Sigurdsson back at the Lane?