In the world of football it is always tough for smaller clubs to keep their star players from going to brighter and greener pastures. This summer was no different as many mid-table sides in the Bundesliga lost their irreplaceable talents. As a result, many teams are going to have a tough term in the new Bundesliga campaign.

1. FSV Mainz 05

Notable Players lost: Johannes Geis, Shinji Okazaki, Jonas Hofmann.

Notable signings: Yoshinori Muto.

Last season was a good one for Mainz as they survived in the Bundesliga once again, just barely hitting the 40 point mark. But heading into this year it looks like they will struggle, losing Johannes Geis to Schalke 04 who, for Mainz, last season compiled a 7.33 rating according to whoscored.com.

Geis also chipped in with four goals and three assists, very good from a defensive midfielder whose set piece prowess will surely be missed. While Okazaki scored an impressive 27 goals for Mainz in the last two seasons, production that will be tough to replace for anyone, much less a mid table side such as Mainz. 

Werder Bremen

Notable Players lost: Franco Di Santo, Sebastian Prödl, Eljero Elia.

Notable Signings: Aron Johansson.

Werder Bremen finished barely above Mainz and 1. FC Köln but managed a 10th place finish with 43 points. But heading into this season it could be a struggle for Werder as they lost main striker Franco Di Santo to Schalke. Di Santo had an impressive 13 goals in the Bundesliga for Werder last time out, and will be a tough player to replace for a club with small amounts of money such as Werder.

As they also lost Sebastian Prödl, a staple in Werder Bremen's back line for the past five seasons. According to WhoScored, he had a 7.2 rating over the last two seasons, an notable contribution in a team that regularly ships goals. 

TSG 1899 Hoffenheim

Notable Players lost: Roberto Firmino, Anthony Modeste, Andreas Beck.

Notable Signings: Kevin Kuranyi, Fabian Schär.

Hoffenheim had a great season last year finishing in 8th with 44 points, barely behind Borussia Dortmund and Schalke. However, the big clubs came calling and Roberto Firmino, who was terrific for the Sinsheim side, was bought by Liverpool.

WhoScored suggest that Firmino had 7.94 and 7.79 match rating the last two seasons. He also provided 23 goals and 21 assists; an incredible rate of production, making Firmino one of the top talents in the league and one that is irreplaceable for almost any club.

Modeste even chipped in with seven goals last term. As Firmino, Modeste and Kevin Volland were responsible for almost all of Hoffenheim's goals, and now that two of them are gone, Markus Gisdol's side look set to have a tough time this year. 

With mid-table sides like the three mentioned above losing stars like Firmino, Geis, and Di Santo and, replacing them with unproven players such as Aron Johansson, they all could potentially struggle. They all did in the first week of the new campaign, as the sides lost on the opening weekend and could have more of the same in store in the remainder.