Pictures emerged of the 48-year-ol former Chicago Cubs star on a night out in London looking virtually unrecognizable.
'Five days until Sammy Sosa's birthday...Here he is in London!' said a user posting a series of Tweets of Sosa and his wife in the city.
The Dominican-born athlete first appeared 'lighter' in 2009, and since then his appearance has been a constant source of speculation amongst sports fans.
Below are just some of the shocked Twitter responces.
One user even compares Sammy to Michael Jackson.
According to an interview with Univision’s Primer Impacto, Sosa did verify that he used a cream that softened and lightened his skin every night before bed.
'It's a bleaching cream that I apply before going to bed and whitens my skin some,' he said.
'It's a cream that I have, that I use to soften [my skin], but has bleached me some. I'm not a racist, I live my life happily.
'What happened was that I had been using the cream for a long time and that, combined with the bright TV lights, made my face look whiter than it really is. I don't think I look like Michael Jackson.'