England's Daniel Sturridge
Speaking on BBC Radio 5 Live's Monday Night Club, Townsend warned Sturridge's approach to his fitness is over cautious and putting his career at the top level in jeopardy, rather than extending it.
Sturridge has started only five Premier League games this season for Liverpool, with a further nine appearances from the bench.
He has two goals and one assist, plus a further four goals from four EFL Cup matches.
Sturridge's last game was more than a month ago on February 4 in Liverpool's 2-0 loss to Hull. Premier Injuries has Sturridge listed as being out with a hip injury, with no return date set.
Townsend says Sturridge must buck his ideas up: "Daniel Sturridge has got to play when he is not 100 per cent or he won't have a career.
"He has got to find solution with his body to make it work better for him. He probably feels hes got genuine reasons why misses game, but the watching football world feels like he needs to sort himself out."
Sturridge's continued absence has left Jurgen Klopp looking elsewhere for solutions, preferring to play Roberto Firmino as a striker even when the England international is fit.
Last season ended with Sturridge scoring in the Europa League final, and netting a crucial goal for England against Wales at Euro 2016, but if there was a tournament this summer, it is doubtful whether he would make the squad.
England's Daniel Sturridge celebrates scoring their second goal against Wales