I may be wrong but don't expect another one.
First of all, Watzke repeated (in last Sunday's Doppelpass) something Klopp mentioned last summer several times: You need to have competition in your squad but at the same time all players need to have a realistic perspective for field time. That's why I reckon that with Immobile and Ginter to be confirmed, our 'incoming' business will be done.
If you look at our current squad, we have Kuba, Aubameyang, Hofmann (as a 'newbie'), Jojic, and Ji; Kevin & Marco can play RAM, too, though they are mostly played as LAM (or centrally as Marco recently).
Re: Jojic: When he joined us, it became apparent that he's primarily foreseen for a Gündogan successor role but that his versatility to play in attacking midfield was another reason. I'm very eager to see Klopp's plans for next season! He had wanted to change it already this season but refrained due to our massive injury crisis.
Yeah, Firmino won´t come. We have no space left in the attacking midfield and won´t add another 15 Mil. € to the investments in the Summer.
If we go by the current status of strong rumors and fixed transfers:
In:
Immobile (ca. 20 Mil. €)
Ginter (ca. 10 Mil. €)
Ramos (9 Mil. €)
Sahin (7 Mil. €)
Ji (free)
Out:
Lewandowski (free)
Schieber (2-3 Mil. €)
Friedrich (free)
That results in a direct investment in the area of 45 Mil. €, which is massive for us.
The 26 man strong squad would then look like this:
GK:
Weidenfeller, Langerak
LB:
Schmelzer, Durm (can also play RB)
CB:
Hummels,
Sokratis, Subotic, Sarr
RB:
Piszczek, Großkreutz (can also play LB,DM,LW)
DM:
Bender, Kehl, Ginter (can also play CB)
CM:
Gündogan (can also play CAM), Sahin, Jojic (can also play CAM), Kirch
LAM:
Reus (can also play CAM and RAM), Aubameyang (can also play RAM)
CAM:
Mkhitaryan (can also play RAM and LAM), Ji
RAM:
Kuba, Hofmann
CF:
Immobile, Ramos, Ducksch
The bold ones would be my regulars as of now, although there could easily be changes depending on the World Cup and Pre season. Weidenfeller, Hummels, Piszczek, Bender, Reus and Mkhitaryan are the only ones, who I would consider safe starter if nothing drastic happens until then. LB, 2nd CB, CM, 3rd AM and CF would be the most competive positions.
Thats one hell of a squad. The strongest we would have since the 90ies. Strong enough to challenge in the three major competitions. Maybe even too big in the offensive midfield, which is why I could see Hofmann and/or Ji going on loan moves. One thing that is noticable is, that there is a clear focus on versatility to ensure enough playing time for most players depending on form. Half the squad can play at least a second position on a good level, quite a few even more.
It is without a doubt impressive, how Dortmund´s head officials (Watzke, Zorc, Klopp) managed to gradually strengthen the squad with relative little money (this Summer will be our first real spending tour in the era Klopp) despite losing key players every season since 2011.
Another point is, that we are not only growing in terms of personell, but also tactically. In the two league winning seasons, we were quite rigid in keeping the 4-2-3-1 formation, which I still consider our main formation for the next season. Learing our lesson in the CL, we added the more compact and defensive 4-3-3 to our repertoir in big games in 2012/2013. In this season Klopp began to adapt even further by trying out the most offensive formation to date in 4-1-4-1, which I could see in the next season vs. very defensive opponents.
Not only our squad strength and financial muscle is growing, but Klopp aswell.