Pierre-Michel Lasogga is a striker at Hertha BSC Berlin. In his 78 games he earned himself a Goalimpact of 109.1. Not too bad for a 21 year old player. According to Die Welt VfB Stuttgart is willingly to pay 4 million Euros, but Hertha doesn't want to sell. Good choice.
Leon Goretzka is considered to be one of the most talented young players in Germany. He is a central midfielder that plays for VfL Bochum in 2. Bundesliga. Although is only 18, he is already playing constantly and is a backbone of the team. However, Bochum doesn't perform particularly well this season and Gortezka only earned a Goalimpact of 99.0 in 40 games. Certainly there is room for improvement given his low number of games in my database and his young age, but it doesn't yet look like he is going to be another Draxler. But with his score he is already among the best playing for Bochum.
Konstantinos Fortounis is an offensive midfielder that recently became a player for the Greek national team. He plays at 1. FC Kaiserslautern and is just 20 years old. Yet in his 76 games he achieved a Goalimpact of just 94.0. Die Welt writes that Borussia Dortmund is willingly to pay 3.5 Million for him. If so, that is going to be for his talent and not for his achievements so far.
Ronny, yet another player of Hertha BSC Berlin, is a Brazilian offensive midfielder in the best football age of 26. Ronny has collected an incredible 25 scorer points in 25 games this season in 2. Bundesliga. This is reflected in his Goalimpact of 117.4 that represents the average of 137 games. He can leave the club without transfer payment as his contracts expires end of this season. Transfermarkt.de lists his value with just 1.5 million Euros. I think he can be a good choice for many lower-end Bundesliga teams.
Caiuby played Bundesliga once in Wolfsburg, but ultimately failed to establish himself. The Brazilian now plays a good season at FC Ingolstadt. Over the 110 games in the database he had an average Goalimpact of 99.4. Not outstanding for a 23 years old left-wing striker. I'm not sure why die Welt thinks he is wanted, but he is not a obvious buy according to the statistics. His upside is more limited compared to e.g. the only 18 years old Goretzka. However, given his rather low market value of 1 million, he may be a good candidate for a reserve team.
I often observe that "hot players" are mostly offensive players. I attribute this to the higher media attention as these are the names that a read on the score boards and are more likely to be high on scorer lists. However, I assume that there are very talented defensive players in the 2. Bundesliga, too. But that will be another story.