Roberto de Zerbi's Tottenham, who have lost both league games this season without scoring, now face a Nottingham Forest side who have beaten them in each of their last four encounters. BBC Sport takes a look at the key themes ahead of Saturday's meeting at the City Ground (15:00 BST). "It's the biggest problem, it's the biggest challenge and it's the biggest target to find the right mentality," De Zerbi said as he reflected on Spurs' defeat to Newcastle that left them bottom of the table.