In footballing terms, this statement is literally the definition of nonsensical.
We have, at a rough count, 7 registered central midfielders in our team. That's 7 players for 2 positions, maybe 3 on the odd occasion.
On the other hand, we have 1 left back, who is injury prone.
You'd have to be half mad not to see that signing a left-back is a much higher priority than another central midfielder.
Marco Silva will be judged on the team he puts out on the field , their performance and the results they get.
He will not be sacked if we have fifteen centre halves or ten central midfielders as long as we win every game, but, he will be sacked if we don't win games. He will be focused on the team that will be played next season not on the players that played last season if he doesn't want to keep them. Players will be moved on but some may take longer than others and it would be folly to sacrifice the 2018/2019 team just to clear out deadwood and I don't believe that is happening.
Leighton Baines is certainly past his best but can do a job at left back and I believe that the manager is assessing all of his squad before dipping into the market and in particular I think he may be looking at Robinson to see if he is ready to contribute.
I may be wrong but when Baines played last season I didn't think that left back was a glaring weak spot in the team.
I have never considered Baines as injury prone but certainly we have to have two players to cover that position.
I do believe we have made contact over the availability of several players but I think the manager may be looking closely at his current crop this week and over the next couple of weeks before making final decisions on some..
