Thomas Tuchel revealed Saul Niguez has been a long-term target for Chelsea and the Atletico Madrid loanee could be in line for his debut against Aston Villa.
The 26-year-old won LaLiga with Atletico last term before joining the Blues on a season-long loan, Tuchel's men reportedly holding a purchase option for £30million (€34m) after paying an initial loan fee of £5m (€5.8m).
As Chelsea look to become the second team, after Manchester United, to reach 600 Premier League wins, Tuchel explained his new recruit's debut has been years in the making.
"He was with us now for two weeks," Tuchel told reporters. "He played on the highest level. I think the picture is very clear. The club follows him for years.
"We know the player very well. He had a quick adaptation with Marcos Alonso and Kepa [Arrizabalaga], in welcoming him into the group.
"He is in the squad for tomorrow. Jorginho can never say no when Italy plays, even when they are 5-0 up, so he is quite tired. It's absolutely possible Saul plays for us."
Saul only managed 22 league starts last campaign, his fewest since 2014-15, but still ranked fourth for attempted tackles in LaLiga for Atletico (57).
Indeed, prior to his departure, only Real Madrid's Casemiro (190) had attempted more tackles by a midfielder than Saul (159) in the Spanish top flight since August 2019.
With N'Golo Kante out injured with an ankle problem sustained against Liverpool, the Spain midfielder could provide vital legs in Tuchel's midfield.
But Tuchel credited those above him in the Chelsea hierarchy for securing the deal from Diego Simeone's side.
"Marina [Granovskaia] was in charge, the best person," the Blues head coach continued. "We were in contact. We knew about the situation.
"We knew things could happen later, we were very aware. I assured everybody that I'm also happy if we cannot bring a player in. We would find a solution in the squad. It was clear, we would try for [Jules] Kounde and Saul.
"In the end, it was possible to get Saul which was a key position for us to have more alternatives. A lot of competition [is] now going on. It's my job to be a good moderator."