The Scottish Premiership giants defeated Rovers 2-0 at home in the third round of the League Cup.
Attacking midfielder Kris Commons put Celtic in the lead at Celtic Park just past the half-hour mark, and Norway international Stefan Johansen made it 2-0 to the Bhoys in the 87th minute.
Following the match, Deila explained why the Hoops could not win by a bigger margin against the Scottish Championship outfit.
RD: It is always difficult to play these games & when you meet a team from a lower division, it’s always tough because they give everything.— Celtic Football Club (@celticfc) September 23, 2015
Over the course of the 90 minutes at Celtic Park, hosts Celtic had 63% of the possession, took 22 shots of which just six were on target, and earned six corners.
Visiting Rovers had 37% of the possession, took five shots of which two were on target, and failed to earn a single corner.