Brighton are "close" to signing Huddersfield midfielder Aaron Mooy, according to manager Graham Potter, while Romaric Yapi has arrived from Paris Saint-Germain.
It us understood that Brighton have fought off competition from a number of Premier League clubs for Mooy.
He has been a stand-out player for Huddersfield in the last two seasons, registering seven goals and four assists over 65 top-flight games, and is set to return to the Premier League following the Terriers' relegation to the Championship.
"Nothing to report yet in terms of finalising it but I think we're quite close," Potter told Sky Sports News.
"We want to try and get that done of course but until then he's not our player.
"In terms of his attributes as a footballer, he's got qualities that I think will fit in well with our group and I think he'll be a good addition if we can get it over the line."
The 28-year-old will become Graham Potter's sixth signing of the season - joining Yapi, Adam Webster (Bristol City), Leandro Trossard (Genk), Neal Maupay (Brentford) and Matt Clarke (Portsmouth).
Yapi, 19, will develop in Brighton's U23 team after signing his first senior professional contract, a one-year deal with the option of extending for another year.
Brighton U23 boss Simon Rusk told the club's official website: "He is another player the club has been aware of for a period of time.
"He is a versatile player and is comfortable at right-back, on the right wing or as a wing back. He is a talented player who has great potential, and I look forward to working with him."
Brighton finished 17th in the Premier League last term, just above the relegation zone, as Potter prepares for his first full season in charge.
Follow Deadline Day on Sky Sports
It's Transfer Deadline Day for the Premier League and Championship on Thursday - and Sky Sports will be bringing you all the latest news on who your club is signing.
Start your day with Deadline Day Breakfast (6am) ahead of a special Good Morning Transfers show (9am), with Deadline Day - The Countdown (4pm) taking you to the 5pm deadline.
The Transfer Show - Deadline Day at 6pm will analyse the big moves before Deadline Day at Ten rounds up all the transfer headlines.