The wait continues for Christian Pulisic. It is now 67 days since the American star last played for Chelsea. A positive Covid-19 test and an ankle injury behind his latest absence from the first team.

Blues supporters have sadly become used to Pulisic's extended periods on the sidelines; they have been frustratingly frequent following his switch from Borussia Dortmund in 2019. And familiarity with the 23-year-old's injury woes has certainly bred contempt.

There are Chelsea fans who would give up on Pulisic, who has missed 38 matches in his two-and-a-half years at Stamford Bridge. Thomas Tuchel will not.

"With players like Christian, who have quick movements, if they feel pain and are not free with their movements, the recovery is not happening," the Chelsea head coach explained yesterday. "So you start all over again. Then if the pain comes back when you have reached a certain point, then you have to pause and again start over.

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Thomas Tuchel on Christian Pulisic injury setback

"We are very close. He was so close to coming back to team training last week but he had a setback and a little reaction with pain, nothing serious. He is very impatient, we can see him suffer in every meeting. He wants to be on the pitch and help us, to do his best. But unfortunately, the injury takes its time."

There can be little blame attached to Pulisic for his current absence, the first ten days of which were spent in self-isolation after contracting coronavirus. That can happen to anyone and pretty much any time. It is a lottery.

His ankle injury, meanwhile, was sustained while on international duty. One heavy tackle and that was Pulisic ruled out for over a month. It was unfortunate but for a player whose primary talent is keeping the ball under control when running at pace, it is a constant risk.

In that respect, Chelsea have been here before. Think back to 2004, the first great Chelsea side. In that squad overseen by Jose Mourinho, there was also a blisteringly quick winger who could alter the path of matches alone. He too struggled with injuries.

That winger was Arjen Robben. Now retired, the Dutchman is considered one of the finest wide players of his generation. He won Bundesliga title after Bundesliga title at Bayern Munich, lifted the Champions League with the German giants, and played in a World Cup final for his country.

But during his three years as a Chelsea player, there was constant frustration that Robben was unable to stay fit throughout an entire campaign.

Per transfermarkt, the former Holland star missed more than 65 matches between 2004 and 2007. There were ankle injuries, a knee surgery, and the more run-of-the-mill knocks sustained during a season. Mourinho was not as understanding as Tuchel.

“It was hard at first because I came with an injury," Robben told The Guardian in 2015. "It was very difficult for me and also for him.

"Of course, he doesn’t like players who get injured. So it wasn’t easy but I always had the feeling I had his confidence. I played some great games for Chelsea but it was unfortunate I had injury problems and I couldn’t do it over a long period."

Robben was sold by Mourinho to Real Madrid for £25m in the summer of 2007. There were injuries too during his first year in the Spanish capital and he received criticism from those in his homeland: Robben was dubbed 'The Man of Glass' by journalists.

"Perhaps if those people had said it when I was older I wouldn’t have cared so much, but I wanted to prove them all wrong," Robben explained in an interview with FourFourTwo in 2019.

"To me, ‘the man of glass’ sounds like they thought I was weak. It had nothing to do with me being weak – it was just that I had a sensitive body at that time. I thought to myself, ‘I don’t break’ and thankfully I proved them wrong in the end."

During his second season at Real Madrid, Robben started working with an osteopath. He continued to do so after joining Bayern Munich in 2010 and he would make more than 300 appearances for the Bavarians over the next ten years.

In that time, Robben proved himself as one of Europe's best. Chelsea – who did enjoy plenty of success without the Dutchman – were left to wonder what might have been if they'd shown a little more patience.

That is why the Blues can't give up on Pulisic. The USMNT star has proved he can make a big impact within the starting XI – were it not for his sparkling form during Project Restart, Chelsea may not have qualified for last season's Champions League, which they ended up winning.

And let's not forget, in his only Premier League outing this season he was on the scoresheet. His strike against Crystal Palace was one of a poacher, something modern-day wingers all have to be. It's not enough to simply create chances, goals are required too.

Next summer, Pulisic will have just two years remaining on his contract at Chelsea. That will be a natural crossroads, a point at which the Blues invest in the American long term or opt to change course. But they should keep Robben in mind. Such a mistake shouldn't be made twice.