Gallardo - he took over one of Argentina's oldest clubs, River Plate, at one of their lowest-ever ebbs - they had been relegated for the first time a few years earlier (Lamela was actually a part of the squad that got relegated). Since his appointment, he's gone on to revolutionize them, returning them to the top of Argentinian football. In the process, he became the most successful manager in their history in just six years, winning the South American equivalent of the Champions League twice.
Barcelona have long been interested in him, but the timing was never quite right, and he's pretty loyal to River. But he's an absolutely masterful coach, who will take Europe by storm when he returns (he was here as a player, with Monaco and PSG).
Marcelino - has had a long career in Spain, and has improved every side he's managed. His last job was with Valencia, where, despite utterly chaotic ownership, he won them their first trophy in yonks and got them into the CL. He was sacked after disagreements with their crazy owner, and took over Bilbao, where he's led them to a cup final at the first time of asking.
Other potentially left-field appointments include Niko Kovac (Frankfurt, Bayern, now Monaco) and Adi Hutter (Frankfurt). Erik ten Hag also a pretty good candidate - he's done well in the Eredivisie, but that's to be expected. More impressive are his consistent long runs in Europe, getting to the EL final in 2018, the CL semi in 2019, and now the EL semi final in 2021.
