Inverness could have been sharper, says manager John Hughes
John Hughes largely praised Inverness Caledonian Thistle's performance in but admitted his side lacked penetration.
"Celtic knew they were in a game," Hughes told BBC Radio Scotland.
"Our ball retention was a lot better, we completed, the shape of the team was good.
"Our penetration in the final third, that wee link-up combination play, could have been a little bit better but that gives us plenty to work on."
Kris Commons fired Celtic in front in the opening minutes at the Caledonian Stadium and Hughes was frustrated to give the visitors "a goal of a start".
Aaron Doran and Graeme Shinnie tested goalkeeper Fraser Forster as the hosts tried to equalise, while top scorer Billy McKay should have done better with a headed chance.
"It's up to us to be slotting him chances," said Hughes, who is hopeful of keeping the Northern Ireland striker when the transfer window opens in January.
"Billy at times is up there on his own."
Inverness start 2014 with a visit from Ross County and Hughes says Caley will be "ready to go" for the Highland derby.