Sterling, who at times played like he had the ball attached to his boot on a piece of string, tormented Kosovo throughout the first half.
But Southgate said: "For a long time we have nearly wanted Marcus to be that option as a No 9 but I'm still not certain that is where he is happiest and where he does his best work".
"I don't think you can have a player that is undroppable, because I think that's a unsafe route for any team and it's probably not healthy for any individual player", he added.
Valon Berisha gave 120th-ranked Kosovo the lead after 35 seconds but England hit back seven minutes later through Raheem Sterling's header and the rampant hosts led 5-1 at the interval with a brace for teenager Jadon Sancho. A run of nine defeats preceded the upturn in form and the visitors - yet to face England at senior level - will be hoping they can add a major scalp to their impressive results of late. What happened with the penalty [for England's second goal], that's what you want to see. Harry Kane has had a slow start in the Premier League with Spurs, but looks sharp under Southgate's England, scoring a hat trick already.
And Southgate has been full of praise for his forward line, also highlighting the attacking depth now at his disposal.
Never did we think after four games that we play for the first place here in England. But we have to remember, as a coaching team.
POOR England! They're finding it so easy it's becoming boring. Sometimes you can overlook the brilliant things that they do, that maybe other countries don't have. "I think there will be a lot of passion on the pitch, a lot of speed, a lot of athleticism and I know Kosovo are also bringing big support, so I think it's going to be a really good night".
England recovered from conceding a goal after 35 seconds to score five times in the first half in a wild 5-3 win over Kosovo on Tuesday (Sept 10), maintaining the team's ideal start to qualifying for next year's European Championship.