Manchester City have recovered from a slow start to the season to muscle their way up the upper echelons of the table despite not having their two frontmen Sergio Aguero and Gabriel Jesus available for much of the campaign.
Fitness issues and respective positive coronavirus diagnosis for Aguero and Jesus have meant that Pep Guardiola has had to get creative in the final third of the pitch for goals.
Costa is a free agent after terminating his contract with Atletico Madrid last month and could be a valuable addition to City’s ranks if a deal can be done.
The 32-year-old Brazilian-born Spanish international has previously starred for Chelsea in the Premier League, hoisting two top flight titles and the League Cup in three-year spell in West London.
Richards believes it would be a no-brainer to bring in Costa’s services as Manchester City attempt to wrestle the title away from Liverpool.
“Manchester City are already on a ridiculously good run of form but if they signed Diego Costa now, he would win them the Premier League - I am sure of it,” former Blues defender Richards told BBC Sport.
“Costa is 32 and I am not suggesting he is a long-term solution for City up front, but the former Chelsea striker is a free agent after ending his Atletico Madrid contract in December, and can sign for anyone for nothing.
“Why not get him in until the end of the season? He would do more than just ruffle a few feathers and be a pain in the backside for opposition defences - he is a proven finisher who would offer Pep Guardiola's side a proper plan B.
“Yes, you would have to cover Costa's wages, but the massive difference he could make to City's season would make that worthwhile.”
