The earliest he is likely to be able to follow fellow double cruciate ligament victim Henry Shefflin back into match action is a possible All-Ireland final tie on September 4.
Shefflin returned to the fray in Kilkenny’s Leinster semi-final showdown against Wexford, on June 11.
And after emerging unscathed from that searching examination at Wexford Park, he also lined out in the provincial final against Dublin on July 3.
Originally, half-back Tennyson, who underwent his surgery a few weeks after Shefflin, had targeted a July return to the Kilkenny panel.
But the Carrickshock clubman’s recovery timeframe was significantly extended by the fact that he was forced to put his rehab programme on hold for the months of January, February and March because of an infection to his knee.
“John Tennyson is working away in the gym, but we don’t know yet when he will be in a position to start doing some training on the field,” said Kilkenny secretary Ned Quinn.
“With less than three weeks to the All-Ireland semi-final, the time is getting a bit short for John to be available for selection for the match.”
Tennyson originally ruptured the cruciate ligament in his right knee during a Kilkenny training session in July 2010.
But remarkably, after missing the All-Ireland semi-final against Cork, he took a full part in five matches — the All-Ireland final loss to Tipperary, and four club ties, the last being the county final defeat by O’Loughlin Gaels in late October.
Two weeks later, he underwent cruciate surgery for the second time, having undergone surgery on the same knee shortly after the 2007 All-Ireland final win over Limerick.
Good news for Kilkenny, however, is that versatile defensive star JJ Delaney will be fit for the penultimate Championship fixture despite being forced to retire with a leg injury at half-time during the Leinster final.
“JJ was back training at the weekend, and we have no worries about him for the All-Ireland semi-final,” said Quinn.