Benfica are looking to cash-in big time as they leverage a sale of at least £20m for Axel Witsel, with both Manchester United and Chelsea training their sights firmly on the Belgium international, talkSPORT reports. Witsel signed for the Portuguese side from Belgian team Standard Liege last summer, and was instrumental in Benfica's making it to the quarter finals of the Champions League. This appears to have, in Benfica's eyes, raised his value more than three-fold, as they prepare to place him on the market for £20m, compared to the £6.3m they paid to Standard Liege for the player. Whether he will end up at Old Trafford or Stamford Bridge depends on several factors, though the residency of several of his national team comrades at Chelsea - including Eden Hazard, Romelu Lukaku, Kevin de Bruyne and Thibaut Courtois - might give him a certain inclination to that side. That said, a taste for glory might steer him towards Man United, after narrowly missing out on his home title while playing for Benfica in the Primeira Liga, losing out to Porto. Compounding this is Alex Furguson's desperate need for younger central midfield prospects, given the winding down of the careers of Michael Carrick and Paul Scholes, while Darren Fletcher remains beleaguered by illness and Anderson is likely hitting the bricks following a few rather underwhelming seasons. Whether that will be enough of an incentive for Old Trafford to trump up the cash to lure Witel away from Roberto Di Matteo and his national brethren is anyone's guess.