Union Berlin are no longer league minnows, says Leipzig boss Rose
Leipzig are in fourth place on 36 points, three behind visitors Union, who have won more league matches this season than leaders Bayern Munich.
"I don't know if they are that small a club," Leipzig's Rose told a news conference. "They have now been around in the league for a few years and are also doing transfers in the seven figures, and I assume earning good money.
"At some point you shake off this underdog tag with your performances. They are now a full Bundesliga member."
Union have won all five matches in all competitions this year, including four straight in the league to move to within a point of leaders Bayern.
"I think this is deserved," Rose said. "It is a team which takes very good decisions on the transfer market, bringing in players who fit the club philosophy which makes absolute sense.
"It means high level of identification, passion, a physical game, a coach who knows how to bring his players' quality to the pitch."
Rose said that Leipzig would be no pushovers, though, having gone unbeaten in the league since September and having won six of their last eight league matches to shoot up the table after a bad start.
"It wont be easy tomorrow but we are in good shape as well. We have started the year well, we are through to the Cup quarter-finals," said Rose, who took over in September to lead their comeback.
"For me it's about the sum of all parts. You have to be good everywhere. Union are strong and well organised, very aggressive. We cannot underestimate them but we want to challenge them. We also can play tough. We will tackle the challenges they will offer."