Former two-time NFL MVP Kurt Warner believes that Detroit Lions quarterback Matt Stafford needs to become more consistent to be considered one of the best signal callers in the league.

The 27-year-old was voted to his first Pro Bowl for his exploits in the 2014 season as he guided Jim Caldwell's team to the playoffs despite injuries to key offensive players Calvin Johnson and Reggie Bush.

However, Warner is adamant that there is still a lot of room for improvement from the quarterback if he is to be considered among the NFL's best.

"I thought [Stafford] was up and down," Warner told the Detroit Free Press. "I think the thing is in the past we've seen his tremendous athletic ability.

"There's still things I think he can clean up with [his fundamentals], and I think if he does, because what I believe as a quarterback is that the more movement you have in your technique, the more opportunity there is to miss.

"That's what you kind of see with Matthew Stafford. He makes some incredible plays, even with his arm in different positions. But the consistency's not there that you need at the position to be one of the top quarterbacks in the league and I think that's where cleaning up the technique will help."

Stafford threw for 4,527 yards along with 22 touchdowns to 12 interceptions in the last campaign.