In 2005, Simms was slated on the depth chart as the backup quarterback, behind
Griese and ahead of former
Cleveland Browns starting quarterback
Luke McCown. Simms got his first snap of the season after
Miami Dolphins linebacker
Zach Thomas was pushed onto Griese's leg with several minutes left in the game on October 16, 2005. Despite the injury, the Buccaneers prevailed 27-13 in the game in which Griese was lost for the season. Simms performed well, completing 6 of 10 passes for 69 yards . Simms got his first start of the season the following week against a weak
San Francisco 49ers squad. While Simms had decent numbers (21-34, 264yds, 1TD, 2INT), his performance was considered poor, as there were many times when he underthrew his receivers, missed open receivers, or incorrectly read the defensive coverage. Simms followed up this performance with about the same performance (25-42, 259, 1TD, 2INT) against the division rival
Carolina Panthers, who were considered a much better team than San Francisco. Since these two losses however, Simms has performed better than expected and has a knack for late-game heroics. He led fourth-quarter charges against fellow division rival
Atlanta twice, as well as the
Washington Redskins. The Redskin game was his best performance of the year as Simms threw for 3 scores as the Buccaneers won 36-35 in a remarkable game. Simms had a much more impressive performance in the rematch against
Carolina on the road. The two losses in this stretch were against the defending
Super Bowl Champion
New England Patriots, and the
Chicago Bears, who were ranked #1 in the league in total defense, and in both of these games, Simms did not throw any interceptions, and was sacked a combined 11 times. He even led Tampa Bay to another fourth-quarter comeback against the Bears but a 29-yard field goal attempt floated wide right giving the Bears a 13-10 victory .
Simms led the Buccaneers to their first playoff berth since their Super Bowl victory in the
2002 season. In the rematch vs. the Redskins Simms led Tampa Bay back again from a 17-3 halftime deficit. With the score at 17-10 late in the fourth quarter, Simms hit Edell Shepherd on an apparent 35-yard TD strike. However, Shepherd failed to maintain possession as he hit the ground. Tampa Bay lost 17-10 in a game where Washington gained only 120 yards of offense, the lowest total for a playoff winner in NFL history .