CELTIC's new signing receives stern words from his old club, Neil Lennon and Ally McCoist give their thoughts on Ian Black, and Hibs" Paul Heffernan believes his side can make the top half of the table, plus more Scottish football news in Saturday's Rumour Mill Overmars: "Stop complaining, Derk" CELTIC'S new signing Derk Boerrigter should stop complaining about his spell at Ajax and focus on his new role at Parkhead, according to Ajax director Marc Overmars. The former Barcelona and Arsenal legend said: "I've called his agent and told him very clearly to tell Derk to watch his words in the future as those who know what happened are sick of reading it. Overmars said that the Dutch champions would have been happy to keep the winger but allowed him to leave ahead of time, and his subsequent comments have "amazed" Ajax top brass. Lennon: "Play well in league or miss out on Europe" NEIL Lennon has warned the Celtic squad that poor domestic performances ahead of the side's Champions League fixtures this season will result in players being dropped. Lennon said: "Last season, I got the feeling that maybe some of the players were saving themselves for the Champions League games. I've made it pretty clear that, if I detect that this year, then there is a distinct possibility they won't play in the Champions League. Now, I'm not giving ultimatums out. I just think it's important they play at full steam in the domestic league games. "Hibs can make top-six" says Heffernan PAUL Heffernan has called on his new Hibs teammates to prove their ability on the pitch, and believes the squad at Easter Road is capable of a top-half finish this season. The striker said: "This is a good squad. It should be very competitive in this league, and we should be looking for at least a top six finish. There are no excuses. We have got the players here - now we have to go out and prove it on a Saturday. Ian Black: Lennon wouldn't pick midfielder, Black "guilty of stupidity" says McCoist CELTIC manager Neil Lennon has said that he would "find it very difficult" to pick Ian Black after the midfielder was found guilty of betting against his own team. Lennon said: "I would take a very dim view of it. I am not aware of it among my own players but it is an unwritten rule that you can't do, (that) and it opens up a huge can of worms later on down the line. In all my time as a player or coach, it is a complete no-no. Rangers manager Ally McCoist believes that Black remains committed, describing his midfielder as "stupid" rather than duplicitous. McCoist said: "I have seen every bet that he's made and... Ian Black is as committed to this football club as he always has been and will do his best for it when he is selected again. It's a nothing bet and the money put on was nothing. That would indicate to me that if he is guilty of anything, it is of stupidity. He is certainly not guilty of anything else. There is a big difference. Scotland to play USA in November THE SFA have confirmed that Scotland will play the USA on Friday 15 November at Hampden. The game will be the last to be played at the national stadium until next autumn as preparations for the Commonwealth Games begin. Thompson could ref in Rio SCOTLAND'S top referee Craig Thompson has been shortlisted for officiating duty at the 2014 World Cup in Brazil. Thompson is on a 19-strong list which will be whittled down to 12 in time for the tournament. Thompson would be the first Scottish official to take part in a World Cup since Hugh Dallas in 2002.