Turkish club Fenerbahçe is preparing to submit an official offer to Italian club Lazio to sign midfielder Matteo Gündozi, while striker Valentín Castellanos is on the verge of transferring to West Ham United for 30 million euros, according to reports from the "Tutto Mercato" website.

Lazio is experiencing greater freedom during the winter transfer window after some restrictions imposed last summer were lifted, allowing the club to make changes to its squad and strengthen the team before the end of the season.

Castellanos has traveled to London to undergo medical examinations with West Ham, and the transfer deal is expected to be completed in the coming hours for 30 million euros, bolstering the English club’s attack this season.

Meanwhile, Fenerbahçe has received the green light to make an official offer for Gündozi, who has previously been linked with English clubs such as Sunderland and Newcastle United. The 26-year-old player is considered a key element in Lazio's lineup this season under coach Maurizio Sarri.

Gündozi, who joined Lazio from Marseille for 14 million euros plus bonuses, has contributed two goals and one assist this season in 15 matches across the Italian Serie A and Coppa Italia, reflecting his importance and ability to influence the midfield.