The right-back has not started a game for nearly two months because of a pelvic complaint, leading to worried comments about his availability from national coach Roy Hodgson earlier in the week.
But Sherwood feels there will be enough time, even if Walker misses the rest of the Premier League season, for him to get back close to 100% before the squad leaves for Brazil.
Hodgson will send his medical team to Tottenham next week to run the rule over the 23-year-old, who has won 10 caps since his debut against Sweden in 2011.
Sherwood told The Sun: "The England physios and doctor will come and assess Kyle and then make a decision on him.
"At the moment there's been no definite decision from my side whether he'll play for Tottenham before the end of the season and from Roy whether he's on that plane to Brazil.
"If he's clinically fit enough to play I think Kyle's fit enough to get himself to a level between now and the start of that World Cup.
"He'd have a few games to prepare. I don't think that's going to be a problem."
Tottenham's World Cup interest was reduced by one player earlier in the week when winger Andros Townsend was forced to have an operation on his ankle, surgery that will rule him out for most of the summer.
But Sherwood expects Townsend to quickly get back into the England picture and enjoy a positive international career.
"He's had the operation and it's gone well apparently, and he's just got to look forward now," Sherwood added. "This World Cup has gone, but he's going to have plenty more.
"He just needs to make sure he gets back fit and playing well for his club side and get that opportunity to play for England again. I'm sure it will come round again."