Speaking to Carlisle's News & Star newspaper, MacDonald paid tribute to a "model pro" and wished him well with the Millers.
MacDonald was on the coaching staff under Paul Simpson as Carlisle won promotion from League Two with an attack spearheaded by the Millers' latest acquisition and he believes that Holmes will be a big asset in Mark Robins' quest to bounce back to League One at the first attempt. "Derek has the experience of what it takes [to win promotion from League Two] from his time at Carlisle", said MacDonald, "I would have thought that Rotherham ... will be among the favourites to win League Two next season".
MacDonald believe Holmes' switch to Millmoor is a "great move" and gave an idea of what the Millers can expect. "He's a model pro ... a decent player ... a good target man and a good finisher. He needs to play every week. He understood the situation of not playing every week [last season for Carlisle] and that it was time for him to move on to pastures new. We wish him all the best".
MacDonald also tipped Chesterfield, bolstered by the signing of Kevin Gray (also from Carlisle) as contenders for the top spot.