I followed Mane quite closely during his time for RB Salzburg. He has been the best player in the Austrian league for most of the time. He formed a great attacking line with Kampl, Soriano and Alan.
He was also one of the main actors when RBS trashed Ajax and defeated Bayern 3:0 in a friendly. I was pretty obvious for everyone following Austrian football that he will leave rather sooner than later so it was not a big surprise that he went to Southampton.
It might have been a good move to go to a mid-table team in one of Europe`s top leagues before entering the main stage.
Kampl who directly joined one of the big guns (Dortmund) is spending most of the time now on the bench. He was not able to adapt as fast as Mane did.
It might sound like an underwhelming signing. Selling AdM and then going down the muppet pecking order Bale-Müller-Pedro-Mane does not sound very attractive but Mane and Memphis could become one of the very best pairing of wingers.
Bayern has also been linked to Mane 2 months ago before the went for Costa. And he was close to signing for Dortmund.
For something like 15 Mio pounds I would take the risk.
Just one thing: His behaviour when he forced his move to Southampton was really bad. He just did not turn up for the game against Mamö. I guess that was the reason for Dortmund to stop negotiations.
No, we backed out mostly because Salzburg wanted more money that we were willing to spend on him.
The interest in Mané first flared up when Blaszczykowski´s future was uncertain by a torn ACL and Hofmann could not back up his promising games as joker when he started. We had a pretty set front four at that time with Reus-Mkhitaryan-Aubameyang-Lewandowski (there was no real indication of Aubameyang moving towards the CF position at that point), but lacked some quality cover at that time aside of the promising youngster Jojic. So we took a look at Mané, which made sense given how much Klopp valued pace.
As far as I understood the initial plan was to replace Hofmann, who would be loaned out to develop, with Mané to bolster the depth in the offensive line. In the end Salzburg wanted 16-18 Mil. € for him, which was not a sum we were ready to pay for a squad player with an outside chance of becoming a starter. Hofmann also impressed in the pre season, which led Klopp to plan with him for the next season. This changed instantly when the opportunity of signing Kagawa came up, though.
I have only seen Mané play for Southampton a handful of times in the last season, but what I saw did not change my initial impression of him at Salzburg:
He kinda comes across as a bit of a street footballer, a trickster who would use his strong acceleration to often get the better of defenders (especially in the Austrian league). His style made him sometimes look like a genius when his tricks worked but it was also quite erratic and often his strong individual scenes did not produce much. This made him overall quite inconsistent.
Now, I do think that Mané could offer quite a bit to a lot of teams. His unpredictability could be useful as impact player to catch an opposing team off guard. I do not see him as a constant figure of a top team, though. For that he simply lacks too much in terms of decision making. A lot of players have the necessary skills to make defenders look like scrubs, but they also know that a simple pass could be the much better action at the right time. This is something I miss about him, to use his skills in a very effective manner.
This is a stark contrast to Pedro, who is a way more straight forward player with a great work rate and selfless style. You know exactly what you get with him. Solid 8/10 performances across the board, not so often above but also very rarely below that.
Now, the most important question is if United would need what Mané has to offer? I don´t think so given that they have with Januzaj and Pereira two players who also still have a bit of that youthful cheekiness but overall more potential IMO.