Although the Midlothian outfit have been able to fulfil their pre-season fixtures – that included games against Edinburgh City and Hearts – things have been far from straightforward as Rose launch their title-challenge bid against Celtic B at New Dundas Park tomorrow.
"We've had a few Covid cases ourselves these past weeks so it has been difficult to try and get some continuity building up to this weekend," Horn admitted. "Guys have been picking it up from their work and then we had a number of them down in London for the Scotland game, so we had to shut down the club for 10 or 11 days.
"It's been frustrating as they've not had a lot of football this year but, if you look at other teams and not just in our division, they are all in the same boat. We'll just have to see how it pans out over the season, but it looks as if Covid is going to cause a few problems again."
Rose are one of the best-supported clubs in the country at this level, underlined by record-breaking season ticket sales this year as they aim to secure that coveted play-off berth against the Highland League champions and a route into the SPFL.
"The club has sold a record amount of season tickets this year to ensure that they can get into the games so that has been hugely encouraging," Horn said. "With the rules changing on Monday again, that will allow for more to come along. When we were playing last season behind closed doors, it just felt soulless a lot of the time.
"Our last competitive game was against Dundee at Dens Park in the Scottish Cup and it was a real strange feeling. It was live on TV and what was such a massive game for the club, it just felt lifeless without fans. Our supporters, especially, always give our players a lift at New Dundas Park.
"We've been pretty successful in previous seasons so I can understand why we'll be one of the favourites this year. But some of the other teams in this division go and continue to spend crazy money. If you look at some of the signings that have been made and the money spent, does it merit it at this level of football? I'm not so sure.
"I think the league is really open this season with at least six or seven who will believe they've got a real chance of winning it. There's no point in saying we expect to go and win the league but we do want to challenge that's for sure."
Horn added: "I think Celtic will be extremely competitive so we're expecting a tough game tomorrow. These players are full-time and represent the two best teams in Scotland. They will be well organised and well drilled so they'll be up for it.
"We don't know who we will be facing because, as it stands, neither half of the Old Firm have submitted their squad lists to the board. But it's one we're really looking forward to and know what we need to do to win the game."