Harlequins star Danny Care, Leicester's Ben Youngs and Dickson himself are at the front of the queue fighting it out for the prized spot, with Joe Simpson of Wasps and Richard Wigglesworth of Saracens also in the running.
Dickson, 27, won his first cap after coming on as a replacement for Ben Youngs against Scotland in the RBS 6 Nations in February, and went on to establish himself as first choice during the 2012 Championship.
The scrum-half impressed for Saints as Northampton's stand-in leader, with regular skipper Dylan Hartley suspended for the run-in, but lost his starting place for England this summer in South Africa, first to the resurgent Youngs and then Care, who returned to the squad after his off-field problems.
But Ellis thinks Dickson - the heartbeat of the Northampton squad - has enough quality to stake a claim to the England shirt and show off the consistency and durability that has driven the Saints to regular top-four finishes in recent seasons
"I think he did earn his place in the England team at the backend of the RBS 6 Nations and he was playing very well," said Ellis, who was speaking ahead of the J.P Morgan Asset Management Premiership 7s Series.
"Lee is very nuggetty, very tough and does the basics very well, while Ben (Youngs) and Danny (Care) offer perhaps that little bit more, that maverick style."
With half a dozen Premiership sides featuring an England-qualified scrum-half knocking on England boss Stuart Lancaster's door, the situation is a far cry from when Ellis was the man in possession of the shirt.
"When I broke into the England team Kyran Bracken had just retired, you had Matt Dawson and Andy Gomarsall and apart from that the cupboard was pretty bare," said Ellis, who is now studying sports science at Loughborough University.
"But then Peter Richards and Shaun Perry came through and suddenly you had a boom in young players.
"Now it's very exciting as they are all great players in their own right. There are five or six who could all play for England and it makes the Premiership very exciting viewing. You know whoever plays nine for England is going to be a very exciting player."
The J.P. Morgan Premiership Rugby 7s Series kicks off on 13 July at Harlequins, with rounds at Sale Sharks and Gloucester Rugby, and the final at Bath Rugby. Visit: www.jpmorgan7s.com to find out more.