The 23-year-old is attracting interest from several Premier League clubs, including Nottingham Forest and Everton, according to the London Evening Standard, with Chelsea open to a sale despite having activated his release clause from Ipswich Town only last summer.
Delap had chosen Chelsea over interest from Manchester United, Newcastle and Everton at the time, signing a six-year contract after scoring 12 goals in 37 Premier League appearances during Ipswich's relegation season.
His first year at Stamford Bridge did not go to plan. Delap managed just two goals in all competitions as Chelsea finished outside the European qualification places and lost the FA Cup final to Manchester City, and he has struggled to make an impression on new head coach Xabi Alonso during pre-season.
Reports suggest Chelsea's asking price has fluctuated in recent weeks, from an initial willingness to accept around £35-40 million up toward the current £50 million valuation, with the arrival of Danny Welbeck from Brighton adding further competition up front and reinforcing the sense that Delap's time at the club may already be over.
He is one of several attacking players Chelsea are looking to move on this summer, with both Nicolas Jackson and Marc Guiu subject to loan and permanent interest as the club looks to streamline a heavily stocked forward line before the transfer window closes on 1 September.
Everton manager David Moyes is understood to remain keen despite the scale of Chelsea's valuation, though it remains to be seen whether any interested club will be willing to meet a fee not far off what Chelsea themselves paid to sign him just twelve months ago.
Chelsea's wider squad trimming extends beyond the forward line, with defenders Benoît Badiashile and Axel Disasi also expected to leave and Tosin Adarabioyo attracting attention from Benfica. Young defenders Mamadou Sarr and Aaron Anselmino are being evaluated for possible loan exits of their own, underlining the scale of the overhaul Alonso is attempting to complete before Chelsea's Premier League campaign gets fully under way.