Varndell has played only 12 senior matches but two tries in Saturday's 40-26 Premiership home victory over Bath took his try tally to 12 and Howard would have no qualms if the Under-21 international winger received a senior call.
Howard said: "Tom's a little bit of work-in-progress but he's got amazing pace. He's just turned 20 and as an England player he has to be something for the future.
"But under the right circumstances you could play him today. You can't match sheer pace and he's fast," added Howard, who was pleased with the way his side played open rugby to secure a bonus point with their fourth try eight minutes into injury time.
"We know where Bath's strengths are with the set-pieces and we tried to open it up a bit.
"As a result opportunist tries happen and they happened both ways. I was proud of the guys and the way they had a go at a different style of game.
"It wasn't perfect but I've got to compliment them for trying something different," he added.