Setien's faith in Umtiti is encouraging to see. However, you really can't ignore the fact that the Frenchman is nowhere near his best. I understand that Quique prefers him over Lenglet because he's considered to be reliable given his experience, always remains comfortable on the ball and doesn't resort to unconventional methods such as sending in long balls blindly. When it comes to playing out from the back, the 28 year old can actually play a crucial role.
However, Umtiti is just a shadow of his former self; he's extremely slow when it comes to tracking back and makes errors on such a consistent basis. He is also easy to beat in the physicality aspect now. I will admit, Lenglet hasn't been at his best this season, but his importance can be seen when it comes to winning the ball back and challenging the opposition attackers. Umtiti almost completely gives up when forwards find spaces to exploit. His injury has severely affected him and no matter how much superior he may be than Lenglet in his prime, his current form is what has to be considered.
Technically, Umtiti is a better defender as he can anticipate passes well. But his legs aren't doing his intelligence and awareness justice anymore. We're seeing a rusty version of Umtiti, one that lacks fine-tuning and finesse. I really love Umtiti, but I think its time Lenglet gets to start the next game. - 38 seconds ago