After starting the season with seven league wins out of seven, the Welsh side hit a slight stumbling block in November with defeats to Ulster and reigning champions Leinster, seeing them drop down to second in the table.
They did not manage to fare much better when attention switched to Europe, recording a draw and loss in their double-header with Racing Metro.
Despite it leaving them without a victory in six games, Tandy could still take plenty of positives out of the performances against the French side.
And with fourth-placed Ulster next to visit the Liberty Stadium before Scarlets come to town, he urged his side to make the most of their last games of 2014.
"It's a massive period for us," Tandy told the club website. "We've got ourselves into a real good position in the league.
"We're sitting second and playing Ulster who are really close to us and Scarlets who are not too far behind.
"We know it's a really important block. I think it's important we take the momentum we've created. I know we've not had the win in Europe, but we've learnt a lot and we can see where we can get to.
"We were disappointed, not with the guys, but that we didn't get what potentially we thought we could have deserved.
"Ulster have a good forward pack, they are a well balanced team, they've got some good backs. They've got quality across the board.
"We know it's going to be a tough encounter but it's one that we know we need to win if we want to be pushing for those top four spots."
Follow us on Facebook, join the conversation on Twitter, sign up to our YouTube channel for extensive match highlights and sign up for our newsletter for regular updates on the GUINNESS PRO12
Guinness PRO12
Suite 208, Alexandra House,
The Sweepstakes
Ballsbridge, Dublin 4, Ireland