"We are a very young team and we have to learn, it is good for this young team to have a taste of what we are going to face in Russian Federation", he added.
Southgate still has time to work on those tactical issues as England have one more friendly - against Costa Rica in Leeds on Thursday - before they fly to Russian Federation for their Group G opener against Tunisia in Volgograd on June 18.
Nigeria were sloppy during the first half and their limp performance in the opening 45 minutes was embodied by Uzoho's blunder, the Deportivo La Coruna goalie allowing Kane's central strike to slip from his grasp.
Top of his to-do list will be resolving which of his inexperienced goalkeepers is his first choice.
Southgate said he hadn't clear seen the incident so he didn't want to publicly reprimand Sterling.
England Manager, Gareth Southgate's having named his provisional 23-man squad for this summer's finals in Russian Federation, will be under pressure to impress in England's final home game at the national stadium before the tournament.
"The fans out there - the incredible atmosphere, the passion that they show".
Sterling went in the book for taking an unnecessary tumble in the box and Eric Dier rose to head wide as England sought to reassert themselves.
"But it's a dream come true for myself to represent England, so it's a really proud moment".
Veteran Ashley Young, slotted at left-back, made a darting run down the wing but was prevented to get his shot on goal by a body of Super Eagles defenders at the midway stage.
But Nigeria pulled one back through Arsenal striker Alex Iwobi.
"Dele Alli's another great player, who came to the club very young".
Nigeria and England qualified for the World Cup with relative ease and both sides will hope to make a mark at the tournament to varying degrees.
But Southgate has tried to freshen up a squad that had gone stale as established stars like Wayne Rooney, Theo Walcott, Joe Hart and Jack Wilshere lost form.
Chelsea winger Moses will be travelling with Kelechi Iheanacho, Ahmed Musa and Wilfred Ndidi to Russian Federation, as the side look to improve on their record of never progressing past the last 16 in their last five appearances at the World Cup.