Chelsea will make an improved offer for Roma striker Edin Dzeko by Monday but need the Bosnia international to compromise over his contract to conclude an agreement.
Chelsea have offered £17.5million for Roma full-back Emerson Palmieri with a further £5.2m in bonuses plus £25m for Dzeko.
Palmieri, 23, has agreed to join but Bosnian striker Dzeko, who is 31, wants a two and a half year contract to match the length of his deal at Roma.
Chelsea are understood to be offering an 18 month deal with a year's option.