Hewett will also compete in the men’s wheelchair doubles at Wimbledon alongside partner Gordon Reid, with whom he has won five titles in SW19.
Asked why he had not been able to add the singles title at Wimbledon, Hewett said his game is “still in its developmental stage on grass”.
He added: “Over the last couple of years at Wimbledon – being on Court Number One, more people watching, more media – these are all new things I’m having to learn which we don’t have week in, week out on the tennis circuit.
“There’s no excuse and I think it is where my game is at if I am being brutally honest with myself.”
Hewett will have to play one extra match than in previous years if he is to reach the final again, with the Wimbledon singles draw having doubled to include 16 players – aligning with the three other Grand Slam tournaments.
“The sport has evolved, the game has evolved and I am a big part of that, but on the grass there are areas of my game that it doesn’t complement as much as the clay or a hard court,” he said.
“I’m trying not to put that pressure on myself currently because it’s Wimbledon. There’s a lot of expectations and pressures in itself, let alone the pressure of trying to complete a massive personal achievement.”