Celtic assistant manager Shaun Maloney says there is "no timeline" for Martin O'Neill's return from the "small procedure" the boss underwent in hospital and the 74-year-old will "make the call" about whether he will be in the dugout for Sunday's trip to Kilmarnock. O'Neill, who was given a one-year contract at the start of the season after leading Celtic to a Scottish league and cup Double after two spells as caretaker last term, was discharged from hospital on Thursday. "It was really positive. He was in good form - loads better than he was Monday, Tuesday. Hopefully that sort of positive feeling he has continues." O'Neill was in the dugout as Celtic started the new Scottish Premiership season with a 1-0 win over Dundee on Monday. Kilmarnock manager Neil McCann wishes Celtic boss Martin O'Neill 'speedy recovery' But Maloney added: "Even for the game at the weekend, it's sort of day-to-day. We saw him last night with regards to the preparation for the game and then he wasn't in today. "I'll speak to him this afternoon and then he'll make a call for tomorrow. And then I'd imagine he'll make the call for the game at the weekend. "But, if it's this weekend, great. If it isn't, then we'll prepare for it with that one."