Locatelli, Bennacer and Neuhaus would be potentially good options IMO. Brozovic would also be a good option at his age due to his contract situation if what I was told in the Sancho thread is anything to go by. He is also still playing to a good level unlike Matic who many Chelsea fans said was finished when he left Chelsea. Brozovic also has high level IQ for a midfielder and has played in various different tactical plans under several very good coaches to a high level domestically, in European competition, and his NT Croatia, so comes with a wealth of experience which would benefit the likes of Jimmy Garner and Hannibal Mejbri in the game today.
From my understanding, Solskjaer wants to press high and play on the front foot. His Molde stint is evidence to that, and he's also said the same whilst he's been the manager at first team level at United. Below I'll provide my subjective opinion on how I believe he can potentially achieve that.
To effectively press high we must begin with the CBs and play a higher defensive line which would mean the CBs would need to defend the channels in 1v1 scenarios. So having a CB who is quick and agile is good, but that's not enough. The CBs must also have the IQ to understand their role and push up and close the space to back up the midfielders who will engage the opposition wide receiver(s) in a 3 pronged wolf pack like attack after the forwards trigger the press. I can go into more detail, but that in essence will create the conditions for the midfield, fullbacks and forwards to press high and counter press which will potentially result in us winning the ball back more effectively high up the pitch, which should in theory lay down the foundation for the midfield, fullbacks and forwards to play their game. That's something we can't do effectively as things stand, hence it's reported that Solskjaer wants to sign a CB who can thwart counters without the aid of his fullback, which makes sense to me.
So once the back line (CBs) creates the conditions for the more advanced midfielders to press and counter press, it's important we have midfielders who can both enforce the press and express themselves on the ball to a high level if we want to sustain attacks. And that's something our current midfield pair aren't good at, hence I believe we need two midfielders to come in to our first 11, which I don't think is gonna happen. I think we might end up with one, and I'd rather that player be someone who is adept at both the offensive and defensive game to a good level. I don't believe Declan Rice is that player. I would rather see a McFred-Locatelli double pivot, rather than a McFred-Rice double pivot, which will raise similar questions some of us are asking currently.
I've also seen people suggest Rice should be bought due to him having the ability to play like the lone ranger role in front of the back line which will free Pogba to attack from the double pivot. That IMO might work against the weaker teams but I'm pretty confident it would back fire badly against any quality team. The reason I say that is due to the left and right defensive zones being very wide infront of the LCB and RCB. If the opposition springs a quick counter on the turn-over we will be left with a potential 5v3 scenario at the worst or a more likely 3v3 scenario which isn't something we should contemplate doing. I don't believe Pogba suits a two man midfield, but if he is to play there, he must simplify his game and play with discipline both on and off the ball, which I don't believe he's strong at, and neither is he adept at enforcing a press/counter press. So if Pogba is to play as the LCM in the double pivot, his zonal partnership will be with Maguire, Shaw and Rashford. Rice would be in a zonal partnership with Lindelof, Wan Bissaka and Mason on the right if I use the players at the club currently.
The attack I feel does need a striker long-term and Sancho who I'm hopeful will arrive. But apart from that, we look set in attack, with just the midfield that needs upgrading, which will bind it all together.