Town keeper James Shea admitted it came a real 'shock' to him when team-mate and close friend Simon Sluga left the club during the January transfer window.
The 29-year-old had been Luton’s record signing when joining for a fee of £1.3m in the summer of 2019, brought in by previous boss Graeme Jones from HNK Rijeka.
After starting the first 18 league games this term, Sluga then missed the 0-0 draw at Nottingham Forest after he was a close contact of someone with Covid when flying back from international duty with Croatia and had to self-isolate.
He returned against Cardiff, but had to sit out the 3-0 win at Blackpool due to illness, as Shea deputised once more, going on to start the next six matches, where he kept two more clean sheets.
The Croatian was then absent from the bench for the 0-0 draw with Blackburn Rovers, Town boss Nathan Jones admitting an offer had come in for him, and two days later he was sold to Ludogorets for an undisclosed fee, the manager stating it was to 'protect the asset' with Sluga potentially leaving for nothing in the summer when his contract was up.
However, asked if it came as something of a surprise to see his team-mate move on so suddenly, Shea said: “It did to be honest.
"I was driving in my car for the Blackburn game and got a text saying 'good luck today mate,' and I was thinking to myself, 'I’m going to see you in an hours time, what are you talking about?'
"He said, 'no the club has accepted an offer for me I’m going to go and speak personal terms.'
"It was a shock to me in that way, so as soon as that happens, you think, 'right he’s going to be going now,' which was a shame as I got on really well with Si.
"I had a real good relationship, we both backed each other whoever played, and it’s just part and parcel of football, the club has got to look after themselves.”
Sluga is yet to make an appearance for his new club, while Shea has started six games since his team-mate departed, with Luton using loanees Jed Steer and Alex Palmer in that time too.
The pair still stay in contact though, with Shea adding: "We’ve been messaging each other, so after games he’s messaged me saying 'well done on a clean sheet.'
"When I got back into the team, we’ve had a message back and forth, but we worked together for three years, I consider Si a friend, so you don’t just stop talking to each other."
On Sluga's time at Kenilworth Road, which saw him recover from a tough start to make 94 appearances, also voted player of the year in 2020-21 by both the Luton Town Supporters’ Trust and the Bobbers Travel Club, Shea added: "He was brilliant, absolutely brilliant he was and he was different Si.
"How can I explain it, he had a dry sense of humour and he was a good laugh, I got on really well with him.
"I can’t speak highly enough of the boy, I got on really, really well with him, he was a massive part of the goalkeeping union and it was really good.”