Romelu Lukaku will be allowed to join Tottenham this summer - but only if Chelsea land £31.5million target Diego Costa from Atletico Madrid. Jose Mourinho will look to revamp his forward line ahead of next season, with Atletico hotshot Costa top of his list. The Portuguese is happy for Lukaku, who is currently on loan at Everton, to leave this summer - but he wants to capture at least two new strikers before sanctioning a permanent move for the Belgian. Lukaku knows his first-team chances at Stamford Bridge will be heavily restricted under Mourinho and feels his long-term future lies elsewhere. Despite the fact he he has started just one Premier League game since joining in 2011, Chelsea are looking to make a profit on Lukaku. He signed from Anderlecht for £18m, but the Blues will start the bidding for the 20-year-old at around £20m given his successful loan spells at West Brom and Everton.