Brighton have signed Polish duo Jakub Moder and Michal Karbownik.
The Seagulls have completed a five-year deal to sign midfielder Moder from Lech Poznan, with the 21-year-old loaned immediately back to the Polish club.
Legia Warsaw defender Karbownik, 19, has joined on a four-year deal and has also been loaned straight back for the rest of the season.
Midfielder Moder boasts one full Poland cap, with Brighton excited by his potential.
"Jakub is an exciting young central midfielder, who has already broken through into the Poland national squad at the age of 21," technical director Dan Ashworth said.
"He is athletic, strong and good with both feet. He is very highly thought of within the national set-up, and we did consider bringing him over straight away.
"However, the loan back to Poznan suits Jakub and us for now – as he will play regularly both domestically and in the group phase of the Europa League, and at this stage that is better for his development."
Karbownik has already won selection to Poland's senior squad, but is yet to win his first cap.
"Michal is another exciting young player, who we are pleased to welcome to the club," Ashworth said.
"He is flexible in terms of position; he can play on the right or left side, at full-back or wing-back, and in midfield."