Shearer questioned Gordon's mental toughness after he started the draw with Barcelona on the bench due to illness. The decision was made despite the winger training with the squad in the morning.
Howe wanted to make clear this morning that no one inside the club was doubting Gordon's commitment or professionalism, despite Shearer's claims after the Champions League clash at St James' Park.
Ahead of their trip to Chelsea on Saturday, the Toon manager began: "He was absolutely willing to play in the game. I know there was a lot of comments but it was my decision not to start him.
"He was prepared to play but in consultation with the medical team we didn't think he was fit to start.
Warming up, Howe also insisted: "Ant is a winner. He is a real competitor and has that streak to him that all top players need. I can only speak really glowingly of him this year.
"It hasn't been a straightforward season but he is in his best mode currently and adapted to a different role really well. There is plenty of pressure and media attention on him and rightly so because he is an England international."
Players showing good mentality
Looking back on the round of 16 first-leg draw with Barca, Howe says the players have shaken off the disappointment of the injury-time equaliser conceded.
He said: "The players have responded well. Big disappointment at the end of the game but a lot of pride in the performance. We have had to take everything in our stride because there's another game around the corner.
"We know the week ahead is a big one but we have to concentrate on Chelsea.
"There is mental challenges for this game we have to try and get right. There will be a lot of focus on the Barcelona game but this game will be a very tough one. Playing them away from home in the Premier League is one of the toughest games we will have.
"The players have become used to producing a positive response to difficult results. A lot of individuals played really well in the game so they will take great confidence from that."
Blame me for poor Prem campaign
Howe has admitted the Champions League is their one change to keep the season alive. Ahead of tomorrow's clash with Chelsea, the Toon manager insists their issues in the Premier League this season have been his responsibility.
"I think you can safely say this season that the Premier League has not gone to plan," said Howe. "We would have loved to have done a lot better than we have.
"We would love to have been more consistent. There have been some good performances in there. Consistency of results has not been there and our away form has not been strong enough.
"We have lost too many games. You can label all that at me and I will take it on the chin. Our plan is to do better."
On what winning at Chelsea would mean knowing Newcastle go to Barcelona next week for the second leg of their round of 16 Champions League tie, Howe admits it could be transformative.
He said: "It could be huge. Let's not forget we won our last game in the Premier League and we are trying to build consistency at last in the league.
"The players know how big it is but you can't change human nature and have to accept Barcelona and Sunderland are on the horizon but I have to make sure they know how important the Chelsea game is."
Bruno is back
Before signing off, Howe also revealed captain Bruno Guimaraes is due back from Brazil next week. The midfielder has been recovering from a serious hamstring injury.
Howe added, "He is back on Monday. Typical Bruno he wants to come to Barcelona and support the team.
"We hope he won't be too far away. Once he is back with us we will have to assess him.
"I know he has been working incredibly hard on his rehab with physios and doctors. I think he will be in a good place.
"Yeah he is such a big player, by the time the international break has ended we hope we will be active and available.
"He will travel to Barca but not in a playing context."