The new coach says the poor physical condition of Robinho was typical of the entire squad when he took over as he cast doubt on his predecessor's training methods
Allegri was sacked after a 4-3 defeat to lowly Sassuolo in January with the Rossoneri languishing in 11th after a disastrous first half of the season and the Milanese remain in that league position under Seedorf's leadership as the campaign draws to a close.
Speaking ahead of Milan's game against Catania on Sunday, the Dutchman was critical of the ex-Cagliari trainer, suggesting that he even failed to keep his players, namely Robinho, in top condition.
"My management must be judged from when I arrived," the 38-year-old told journalists.
"What happened before does not concern me. It is pointless to speak of [my coaching] philosophy. I have just started as a coach and I have more to do. Now I have to pull the most out of each player and next season will be completely different.
"Robinho, as well as the whole team, has had a large physical deficit and could not express all his talent. He was not fit when I arrived but he has shown real desire and he is one who runs the most. He has certainly been one of the most positive in training and I think his moment will come."
Seedorf, who himself made 431 appearances and scored 60 times for the Rossoneri, stressed his belief that things were improving for his side and hoped that Milan fans could see the progress being made.
"Things are coming together," he added.
"[Philippe] Mexes is a real leader and [Daniele] Bonera is making the defence solid.
"I'm not surprised by Mexes' performances. Since I got here he's been among the most proactive of the group, one of the leaders and this is why I gave him the captain's armband in Naples. Now we see the fruits of that work because Philippe is giving personality to the team.
"Mario [Balotelli] too is showing continued growth, on and off the field, including in his private life. Also his behaviour with the referees I now consider exemplary. We're already better now than when we faced Atletico Madrid [in the Champions League last-16]."
Milan sit 11th in Serie A with 45 points from 32 games.