The Red Devils have agreed a fee with the Portugeuse club for the transfer of the Swedish international to Old Trafford. Lindelof's move to United is subjected to medical and the player will travel to Manchester to complete his move.
Keane was linked heavily with a move to United and the Times earlier reported that the former United man is set to become Mourinho's first signing of the summer transfer window. However, another report from the Times claims the former Real Madrid and Chelsea manager has ended interest in re-signing the England international after Lindelof's capture.
Wilkins believes Lindelof has "done absolutely nothing" and says Keane would have been a better addition to United's back four than the 22-year-old Swede.
"We've got young Keane has done exceptionally well at Burnley, we're looking to bring him back at Manchester United for £28m, all of a sudden Lindelof is 30 [million]," Wilkins told Sky Sports, as quoted by Goal.com.
"Now, when we bring someone in from Europe, it always starts with a three. This guy has done nothing. Absolutely nothing.
"Yet Keane has played a season exceptionally well in the Premier League, but we're talking £25m. This guy's coming in at £32m, £33m. Can he do it? We know Keane can, yet we're prepared to spend..."
"It always starts with a three, or a four, or a five. No one gets anything cheap from Europe because it's the Premier League."
Lindelof has won the league on three occasions with Benfica, while also winning other domestic competitions with the Portuguese outfit. In addition to this, he won the European Under-21 championship with Sweden in 2015 and started in the national side's fixtures in the Euro 2016.
With United ending their interest in Keane, Everton have re-emerged as a favourite in landing the former Red Devils' defender. The 24-year-old English centre-back wants regular playing time next season as he looks to seal a berth in England's squad for the 2018 Fifa World Cup in Russia.