It's no secret that Celtic have seriously underperformed this season.

Manager Neil Lennon has put his side's failings down to a handful of reasons. No supporters inside stadiums to give them a kick up the backside when they need it. Covid-19 decimating his squad at different points throughout the campaign. He even claimed recently that some things had gone on behind the scenes that he couldn't divulge.

But one of the more significant challenges for Lennon and his players, especially his new signings, has been the impact of moving to Parkhead in the midst of the global pandemic without being able to bring their families. Shane Duffy, Lennon says, has struggled to adapt. Vasilis Barkas has so far failed to make the transition to Scotland. Hatem Abd Elhamed - though not a new signing this season - was seriously homesick, with his wife and little boy stuck thousands of miles away in Israel.

The defender had to head back home for the good of his mental health, there was no question. And football takes a backseat when it comes to loved ones.

One player who knows all about the sacrifice of living and playing abroad is former Dundee Utd man Johnny Russell. The Scotland cap has been plying his trade in the MLS with Sporting Kansas City for four years now and had been loving every minute until the virus hit. Now he has not seen his extended family for longer than a day in almost a full calendar year.

That's why he sympathises with the Celtic stars who have struggled. Life can be lonely when the training pitch and the same four walls of an empty house are the only two places a footballer can go.

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"Boys like Elhamed in a different country and they don't have anyone there," Russell told Herald and Times Sport. "You're on your own, don't have your family around. Normally you train and you're with all the boys, but even that is a bit restricted just now. People might say, 'Oh they're footballers', but that doesn't matter. It is hard and I completely understand anyone in that situation who is finding it tough. I've been away from my kids for three-and-a-half weeks even just now and I'm struggling with it.

"You need your people around, no matter who it is, and when you don't get to see them it's lonely. It's tough. I completely sympathise with guys like Elhamed and Shane Duffy. And anyone, not just players, anyone who has to work away and don't get to see their families.

"I only got to see people for a day on Christmas because of quarantine which ended on Christmas Eve, saw them on Christmas Day and pretty much had to leave right after that. So I've not really seen anyone for about a year. It's been really tough being away from home.

"FaceTime has been good because you get to see their faces but it's not the same. It's been tough but it's the way things are, it's not just me who is dealing with it.

"Over here [in Kansas] it's a lot more relaxed with the restrictions so we can go to restaurants and things like that. There are curfews but it's similar to the UK when it opened where you could go to bars and restaurants if you kept spaced apart. It's better to have that little bit more freedom. But I'm here on my own, I go train, do bits around the house and that's me for the rest of the day.

"It gets to about four or five-o'clock and everyone back home is in their beds! I just can't wait to get the family back out soon."

Russell knew what he was getting himself in for when he moved over to the US, as did Elhamed when he made the switch to Glasgow. The problem since being that both transferred before the absurdity of a worldwide pandemic.

Elhamed's wife and child, it is understood, were denied visas to move over with him and things got even tougher when the freedom of travel became impossible. Russell, though, sees the bigger picture. He misses his family, like anyone would. But he remembers making the call to move and he does not regret it. He just wishes there was a hint of normality back in his life.

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"How many nurses and people like that have been working away and have had to see their families through the window and all that," he added. "It has been a horrible time for everyone and when you don't have that interaction, especially the guys who have kids and a wife, they've maybe not seen them on a daily basis for how long. It's going to get to you.

"When you make a decision to go abroad somewhere to play, you know you're not going to see people as often as you normally would. You consciously know that but the situation for the last year has exacerbated that and made it a lot more difficult. I miss not seeing my mum and my brothers and sisters but I've been here four years now, so it's not too unusual for me now.

"Even when I played in England with Derby I wouldn't see everyone all that often. So I completely understand how hard it can be."