EXCLUSIVE: Injury expert Ben Dinnery on Man United's issues & James' struggles at Chelsea

Dinnery keeps a constant finger on the pulsating life of the Premier League, particularly on the players not playing.

"He comes with a vast amount of experience, and you don't work in clubs like Arsenal or are being touted by clubs like Manchester United if you're not capable and comfortable at working at an elite level," is how he thinks of O'Driscoll, who nevertheless was the target of a fair bit of criticism at one point.

"Arsenal gained a bit of a reputation as a club that carried a lot of issues, but Gary O'Driscoll is at the very top of his game. He knew Arsenal inside out and now Manchester United are hoping that he can revamp the medical department and pinpoint where their issues may be."

Players like Lisandro Martinez, Casemiro, Raphael Varane, Christian Eriksen and Luke Shaw have been absent for long periods of time, but don't expect the former Gunners doctor to simply wave a magic wand, Dinnery warns.

"He is now a big cog in this vast Manchester United machine, but he knows his stuff, I'm sure he'll do an excellent job," he said.

"At Arsenal, among other things, they looked at the firmness of the ground on the training pitches. Ultimately the clock is ticking once a player picks up that injury, it's about getting those players back on the pitch as soon as possible, none more so than at clubs like Manchester United. We're talking about high-profile players who have a lot of experience."

One of those is Lisandro Martinez, who only recently returned from his foot injury. Dinnery is wary of believing all is good and well with the Argentine World Champion.

"As with any injury, and particularly long-term injuries, there are no guarantees that he's past his issue," he continued. "You can do a lot of work off the pitch in terms of testing, but once you cross the white line and you're involved in the cut and thrust of the Premier League the intensity is unparalleled."

Dinnery will follow the Argentinian closely over the next five to eight games before feeling certain that he is back to stay, but five to eight games is something Reece James never seems to reach.

He has once again suffered a setback just when people thought he was about to re-enter the line-up at Chelsea. Tribal Football already spoke once to Dinnery this season regarding the apparent ongoing issues with the Blues captain, so what is going on?

"You have two precursors to injury," he said. "One is history and we know from recent times that Reece James is not a player who you can rely on to play week in and week out. It is all about managing the workload of a player, about finding that balance between getting the player the right amount of match fitness to maintain his sharpness, while also just easing him back.

"We've seen that done with Ben Chilwell, who was starting in the Carabao Cup and then back on the bench. The difficulty is always going to be, how are we going to prepare Reece James in mid-season, when Chelsea are playing big games in the Carabao and FA Cups and the Premier League?

"Then he's playing catch-up, trying to gain both momentum, freshness, and the sharpness needed for the Premier League. There's not much hiding place for a player like Reece James, who is probably always going to be on the cusp of really pushing his body to the limits."