Marseille want to find a replacement for Georges-Kevin N'Koudou before sanctioning a move to Tottenham, according to Sky sources.
The two clubs are in talks over a deal for the France Under-21 winger, who has been of interest to Spurs for some time.
N'Koudou caught Tottenham's attention while they were scouting Belgium striker Michy Batshuayi, who joined Chelsea last month.
It is understood Marseille have asked about taking Spurs' young Cameroon international Clinton N'Jie on loan as a replacement for the 21-year-old, but this is proving a sticking point in negotiations.
N'Jie, who signed for Spurs from Lyon last summer but has hardly played due to injury, wants to stay and fight for his place and Spurs still have high hopes for a player that cost them £12m.
Ideally, Spurs would like to keep N'Jie and sign N'Koudou, with reports in France suggesting a fee for N'Koudou's transfer has been agreed at £10.8m.
Marseille are known to have been in some financial difficulty, but sold Batshuayi to Chelsea for £33m and left-back Benjamin Mendy to Monaco for a reported £7.6m, so they can afford to take their time to find a replacement for N'Koudou.
N'Koudou made 28 appearances for Marseille last season after joining in a £1m deal from Nantes and was among 37 players who received votes in UEFA's Best Player in Europe award, decided by journalists from all 55 member nations. However, he did not make Monday's final 10-man shortlist.