Timothy Fosu-Mensah is set to join Crystal Palace on a season-long loan from Manchester United, with the defender due for medical on Monday.

Frank de Boer has been searching for additions to his defensive ranks having already signed Jaïro Riedewald from his former club Ajax and has registered an interest in both Arsenal’s Calum Chambers and Bruno Martins Indi of Porto, who spent last season on loan at Stoke.

In the meantime, De Boer has acted to provide cover for his regular right-back Joel Ward by agreeing a move for Fosu-Mensah, the 19-year-old who began his career under the Dutchman at Ajax. He made eight appearances under José Mourinho last season having made his debut for Louis van Gaal in February 2016 and can also play in central defence and midfield.

United also confirmed on Monday that the 20-year-old defender Cameron Borthwick-Jackson will join Leeds United on a season-long loan. Their departures could help facilitate a move for Paris Saint-Germain’s Serge Aurier, with reports in France also linking the defender with Internazionale.

Manchester City will hold talks with the representative of Patrick Roberts on Monday, with Nice understood to be one of several clubs interested in taking the 20-year-old on loan. Roberts spent 18 months at Celtic, where he helped Brendan Rodgers’ side remain beaten throughout the SPL season, scoring nine league goals. They would like to agree a new deal for the former Fulham forward, although it appears likely that he will head overseas.

Elsewhere, Barcelona have indicated to Nice that they are prepared to pay the €40m (£36m) release clause for Aurier’s Ivory Coast team-mate Jean Michaël Seri. Marco Veratti had been Barça’s primary midfield target this summer but the Italian’s decision to remain at PSG, where he is expected to sign a new contract worth €12m per year (£10.8m), has forced coach Ernesto Valverde to turn to Seri.

The 25-year-old has also been tracked by Arsenal, Everton, Swansea and Tottenham this summer and set up goals in both legs of Nice’s Champions League qualifying victory over Ajax last week. The French side, who have confirmed the signing of Wesley Sneijder on a free transfer, face Napoli in the first leg of the final play-off round next week and would prefer to keep Seri until then. Nice are also set to sign Allan Saint-Maximin from Monaco ahead of Monday’s deadline for registering new players for the Champions League playoff, having reportedly agreed a deal to sell Dalbert Henrique to Inter.

Barcelona are also interested in Ousmane Dembélé as they attempt to replace Neymar following his world record transfer to PSG, with Borussia Dortmund understood to have told them the France forward will cost up to €120m. Philippe Coutinho remains a target, with reports in Brazil on Monday stating that Barça are increasingly confident of convincing Liverpool to sell him.

Algeria winger and former Everton target Rachid Ghezzal is set to join Monaco on a free transfer after leaving Lyon in June.