Tottenham have offered Celta Vigo around £10m for midfielder Pape Cheikh Diop.
The bid is significantly short of the buy-out clause in his contract, which is believed to be £25m.
Diop, 20, has impressed for Celta in La Liga and has been linked with a number of other leading European clubs in recent months.
The Spain Under-19 international (pictured above on the left) is one of several players Spurs have been eyeing during the transfer window.
Another is Ajax’s Colombia international Davinson Sánchez and talks have taken place with the Dutch club over a potential deal for the highly-rated defender to move to north London.
Last season’s runners-up remain the only Premier League club not to have made a signing so far this summer.
And manager Mauricio Pochettino has warned that needs to change if another title challenge is to be sustained this time around.
Speaking at his post-match press conference following Sunday afternoon’s 2-0 win over Newcastle at St James’ Park, Pochettino said: “We need new players to bring some energy to the team and to challenge our best players – that’s always important.”
The Argentine added: “We need to sign some players. It’s important to improve the squad and to create competition.
“We have 10 months ahead, our competitions, and we will need a lot of energy, and more quality.”