Bruce also gave an injury update ahead of his side's clash with Burnley at Turf Moor this weekend, as his two goalkeepers returned to training.
Lenihan made his debut for the Republic of Ireland under-21s in May this year, and signed for Hull in the summer from League of Ireland side Cork City.
Bruce has also confirmed that his two goalkeepers Allan McGregor and Steve Harper have returned to training after being sidelined through injury.
McGregor has been suffering with a shoulder problem, whilst Harper suffered a bicep injury whilst deputising for McGregor during the 2-2 draw with Arsenal at the Emirates Stadium last month.
As a result, Hull have been relying on Eldin Jakupovic to fill in for the injured pair during a long spell of the draw at Arsenal, against Liverpool at Anfield and during the 1-0 defeat to Southampton at home last weekend.
Bruce's side will be hoping to bounce back from the defeat to the Saints by winning against Burnley this weekend, who have yet to register their first victory this season since returning to the top flight. Burnley currently sit bottom of the Premier League with just four points.