Angel Rangel snatched an injury-time draw at the Keepmoat Stadium to leave Swans with just one defeat in their previous 10 league games, and victory over Pompey would put them level in second place with rivals Cardiff for a few hours at least before they travel to leaders QPR on Saturday.
"Getting a point at Doncaster was a decent result given the timing of our equaliser," Cotterill told the South Wales Evening Post. "They are a good side who like to play football and they will be up there pushing for the play-offs at the end of the season.
"But the point means we keep ticking over and adding to our total.
"Now we have to make sure we maintain our good run against Portsmouth on Friday night. Three points would really help us.
"If we don't put in a performance and get a result, then it takes something away from performances like the one at Doncaster."
Source: PA
Source: PA