Manchester United are set to sign French defender Leny Yoro. He may not be the only centre-back signing. Manchester United have struck a deal to sign Leny Yoro from Lille, and as exciting as it is – he alone may not be enough. While Leny Yoro and Lisandro Martinez could strike up an exciting partnership, we saw last season how injuries can really test the Manchester United squad. Aside from Yoro and Martinez, alternate options Harry Maguire, Victor Lindelof and Jonny Evans are all over the age of 30. READ MORE: Manchester United confirmed signings, transfers in, out, loan exits, releases for 2…