Arsenal have had an offer of €35m (£30.74m) turned down by Monaco for Thomas Lemar, with the French club adamant they will not sell the winger.

Arsène Wenger is determined to reinvigorate Arsenal’s attacking options as he struggles to retain his star player, Alexis Sánchez, who is wanted by Manchester City among other clubs, and he has targeted Lemar as one possible solution.

Lemar, who has long been coveted by Tottenham, likes to play on the left flank – the position Sánchez has occupied most regularly at the Emirates Stadium. The 21-year-old is quick and skilful, and he enjoyed a stunning season last time out, when he helped Monaco to win the Ligue 1 title and reach the semi-finals of the Champions League.

He is understood to be keen on working under Wenger, who managed Monaco towards the start of his career and retains a tremendous reputation in French football. But the Monaco vice-president, Vadim Vasilyev, who is fighting to keep a clutch of his stars, has told Arsenal they cannot have Lemar and that the stance is non-negotiable. Whether the London club accept that remains to be seen.

Lemar moved to Monaco from Caen in 2015 and is under contract until 2020. The club are happy to grant him new and improved terms. He has five France caps.

Monaco have sold the attacking midfielder Bernardo Silva to Manchester City in a deal worth £43.6m, while the £40m-rated left-back Benjamin Mendy is also wanted by City and the midfielder Tiemoué Bakayoko is on the verge of joining Chelsea for around £40m.

Wenger has been keen to do his transfer business early this summer and he has secured the left-back Sead Kolasinac on a free transfer from Schalke. He has overseen a £44m bid for the Lyon striker Alexandre Lacazette, which was rejected.

Ryan Sessegnon, the 17-year-old Fulham left-back and another player Arsenal have tracked extensively – together with every other top club in England – has signed his first professional contract, to 2020. Sessegnon feels that he owes a debt to Fulham, where he has progressed through the academy, and he will stay with them for the forthcoming season, at least.

Tottenham have also had a serious interest in Sessegnon and, as with many of their rivals, including the Manchester clubs, they had hoped that the player would opt against signing a professional deal at Fulham, which would, potentially, have allowed them to prise him away for compensation costs. That will now not happen.

Fulham were adamant that Sessegnon was not for sale and they hope that he can be an integral part of a promotion push from the Championship. He is poised to link up with the England squad for the European Under-19 Championship in Georgia, after what was a breakthrough season for him.

Sessegnon, who turned 17 in May, made 30 appearances in all competitions for Slavisa Jokanovic’s team, scoring seven goals.

The former England international Scott Parker, who has been at Fulham since 2013, has announced his retirement.