Jones’s back-row options have been depleted by injuries to Chris Robshaw and Billy Vunipola, while James Haskell’s comeback from foot surgery was aborted after 35 seconds due to concussion.
A possible reinforcement is 20-year-old Underhill, a flanker of rich potential who is being mentored by World Cup winner Richard Hill but has made only 24 appearances for the Ospreys.
While Jones insists Underhill’s forthcoming move to Bath means he can be picked by England – Twickenham allows the selection of players based outside of the Aviva Premiership only in exceptional circumstances – he believes this RBS 6 Nations has arrived too early in his career.
“Sam is available now – he wants to play for an English club and has signed for one,” Jones said. “If we wanted to force the issue we could, but we’ll probably look at considering him for the summer tour to Argentina because he hasn’t done enough.”
Jones will keep faith with the players who completed an unbeaten 2016 consisting of 13 successive Test wins when he names his 34-man squad for the Championship this morning.
Ellis Genge could be drafted in to add cover at loosehead prop, but with Jones insistent that Joe Marler might yet be fit for the opener against France on February 4, the Leicester front-rower may not be needed.
The succession planning at full-back has already begun with Elliot Daly and Anthony Watson the alternatives to Mike Brown, who remains first choice but will be 34 at the next World Cup.
Uncapped Saracens playmaker Alex Lozowski is also a possibility with Jones believing he should not be confined to fly-half.